This is the ABC of the world of hydraulics, without the ability to read circuit diagrams it is difficult, and sometimes impossible, to understand the structure of a particular hydraulic system. The table below will give you a basic idea of ​​the graphic designation of some hydraulic components. I would like to draw your attention to the fact that the symbols in the table comply with the ISO standard (ISO 1219-1) and in some cases may differ from the ESKD and GOST symbols.

But sometimes, even having learned all the symbols, there are problems with understanding why a particular symbol is used in the chain and how it works in real life. We will try to analyze all these questions later, and in this article we will talk a little about such simple and most common graphic symbols as lines.

• The main element of any scheme are lines of different types. Most often there are solid black lines, which we will call the main or basic. This type lines are used in the design of basic symbols, as well as to indicate pressure (high pressure), drain (low pressure) and suction lines.
• The other type is the dash-dotted line. This line is most often used to group components within a single node. An example would be a pilot operated valve or any other assembly containing cartridge type valves.
• The third type is the dotted line. As a rule, it is used in two cases: to indicate drainage and pilot hydraulic lines. Pilot lines use hydraulic power and serve to control other valves or alarms. Drainage lines are any fluid leakage lines that require a designation on the diagram.

Particular attention should be paid to the intersections and connections of lines:

1. Not all crossed lines are junctions (the distinguishing feature of a junction is the point at the intersection)
2. Not all intersecting lines in the diagram intersect in a real hydraulic system

As already mentioned, the main line is also involved in the outline of the figures of the main components of hydraulic circuits. There are three most common shapes: circle, square and rhombus. Almost all hydraulic symbols uses one and the same figures. At the heart of the graphic representation of the hydraulic motor, hydraulic pump, as well as measuring instruments lies a circle. The square is common in the design of valves and distributors. Rhombus is used for filters and heat exchangers.

Description	Designation on the diagram
Basic lines
Pilot lines
Drainage lines
Boundary lines
Electrical lines
Direction of fluid flow (hydraulics)
Gas direction (pneumatic)
Direction of rotation (Direction of rotation)
Lines crossing
Line connection
Quick Coupling (BRS) (Quick Coupling)
flexible line
(Variable Component)
Pressure Compensated Components
Tank open type(atmospheric pressure in the tank) (Reservoir Vented)
Overpressure tank (closed type) (Reservoir Pressurized)
Drain line to tank (above liquid level)
Drain line to tank (below liquid level)
Electric Motor
Spring hydraulic accumulator (Spring loaded accumulator)
Gas accumulator (Gas charged accumulator)
Heater (heater)
Heat exchanger (cooler) (cooler)
Filter (Filter)
pressure gauge
Thermometer
flow meter (Flow meter)
Pressure relief valve ("breather") (Vented Manifold)
Pumps and motors (Pumps & motors)
Fixed displacement pump (non-adjustable) (Fixed displacement)
Fixed displacement pump (unregulated) reversible
Variable displacement pump (adjustable) (Variable Displacement)
Variable displacement pump (adjustable) reversible
Fixed displacement hydraulic motor (non-adjustable)
Fixed displacement hydraulic motor (non-adjustable) reversible
Variable displacement hydraulic motor (adjustable)
Variable displacement hydraulic motor (adjustable) reversible
Pump-motor (unregulated) (combined pump and motor)
Pump-motor (adjustable) (combined pump and motor)
(Hydrostatic transmission)
hydraulic cylinders
(Single acting)
(Double Acting)
Double acting cylinder with double rod (synchronous) (Double actin, double end rock)
Cylinder with damper(Cushion)
Cylinder with adjustable damper (Adjustable Cushion)
Double-acting differential hydraulic cylinder (differential pision)
Valves
Check valve
check valve controlled (Check valve)
Valve "or" (Shuttle valve)
Throttle unregulated (Throttle valve-fixed output)
Throttle adjustable (Throttle valve-adjustable output)
Throttle adjustable with check valve
flow divider (Flow dividing valve)
Normally closed valve (Normally closed valve)
normally open valve (Normally open valve)
Pressure regulating valve - non-adjustable (Pressure limiting valve, Fixed))
Pressure regulating valve - adjustable (Pressure limiting valve, Variable))
Pilot operated valve with external drain line (Pilot operated, External drain line))
Pilot operated valve with internal drain line (Pilot operated, internal drain line))
Safety valve (Pressure Relief Valve(safety valve))
(pressure switch)
Tap (Manual shut-off valve)
Control type
Spring (Spring)
Spring return (Spring return)
2-position, with two extreme positions and neutral
2 position, 2 line
2 position, 3 line
3 position, 4 line
Distributor with mechanical feedback (Mechanical feed back)

08.09.2011 21:07

Usually, in the drawings of hydraulics, the lines are indicated by lines, and the working bodies and the normal. equipment is shown by symbols. On the same drawings, most often, special devices are shown semi-constructively.

The figure reflects the most popular symbols for hydraulic circuits, which were approved during the Soviet era:

1 - general designation of an unregulated pump without indicating the type and type;
2 - general designation of an adjustable pump without specifying the type and type;
3 - vane pump (rotary vane) double-acting unregulated types G12-2, 714-2;
4 - double vane (rotary vane) pumps with different capacities;
5 - unregulated gear pump type G11-1;
6 - unregulated radial piston pump;
7 - adjustable radial piston pump types: 11R, NPM, NPCM, NPD and NPS;
8 - pump and hydraulic motor axial piston (with swash plate) unregulated;
9 - pump and hydraulic motor axis-piston (with swash plate) adjustable types: 11D and 11P;
10 - general designation of an unregulated hydraulic motor without specifying the type;
11 - general designation of an adjustable hydraulic motor without specifying the type;
12 - plunger hydraulic cylinder;
13 - telescopic hydraulic cylinder;
14 - single-acting hydraulic cylinder;
15 - double-acting hydraulic cylinder;
16 - hydraulic cylinder with double-sided rod;
17 - hydraulic cylinder with differential rod;
18 - single-acting hydraulic cylinder with piston return with a spring rod;
19 - servomotor (torque hydraulic cylinder);
20 - apparatus (main symbol);
21 - spool types G73-2, BG73-5 controlled by an electromagnet;
22 - manually operated spool type G74-1;
23 - spool with controls from the G74-2 type cam;
24 - check valve type G51-2;
25 - pressure spool type G54-1;
26 - pressure spool type G66-2 with a check valve;
27 - two-way spool type G74-3 with a check valve;
28 - safety valve type G52-1 with overflow spool;
29 - pressure reducing valve type G57-1 with a regulator;
30 - four-way crane type G71-21;
31 - four-way three-position crane type 2G71-21;
32 - three-way valve (three-channel);
33 - two-way valve (through passage);
34 - damper (unregulated resistance);
35 - choke (unregulated resistance) types G77-1, G77-3;
36 - throttle with regulator types G55-2, G55-3;
37 - general designation of the filter;
38 - lamellar filter;
39 - mesh filter;
40 - pressure switch;
41 - pneumatic accumulator;
42 - pressure gauge;
43 - pipe connection;
44 - pipe intersections without connection;
45 - plug in the pipeline;
46 - reservoir (tank);
47 - drain;
48 - drainage.

On the this moment there is no common standardized way line designations on hydraulic diagrams. The most common method is considered to be, firstly, that the line that connects the devices is marked with a thick solid line, secondly, the line that passes inside the devices is marked with a thin solid line, and thirdly, the drainage line is indicated with a thin dashed line.

The places where different highways connect are indicated by a dot and a line, position 43 in the figure, and the intersection of the connections is usually indicated by a bypass sign, as shown in the figure at position 44.

The most complete scheme can be found in GOST 2.782-96. You can download it on our website.

Overview of Schemas

Schemes are design documents, on which the component parts of the product, their relative position and relationships between them are shown in the form of conditional graphic images.

In modern technology, mechanical, pneumatic, hydraulic and electrical devices and drives are widely used. The study of the principle and sequence of operation of such devices according to the drawings general types and assembly drawings are often difficult.
Therefore, in addition to drawings, special schemes are often drawn up, which make it possible to understand the principle and sequence of operation of a particular device much faster.

Schema types

Schemes, depending on the main purpose, are divided into types, each of which is usually indicated by a number:
1 - structural;
2 - functional;
3 - fundamental;
4 - connections (mounting);
5 - connections;
6 - common;
7 - location, etc.

Structural diagrams serve for general acquaintance with the product and determine the relationship of the component parts of the product and their purpose; circuit elements are drawn in simple geometric shapes(rectangles) and straight lines or analytic notation allowing the use computer.

Functional diagrams explain the processes occurring in the product or in its functional part; they must indicate the names of all the depicted functional parts.

Schematic diagrams (complete) define full squad elements of the product and the relationships between them, giving a detailed understanding of the principles of operation of the product.

Connection diagrams (mounting) show the connections of the component parts of the product, as well as the places of connections and inputs, and identify wires, cables, pipelines and their fittings.

Connection diagrams show the external connections of the product to utilities or devices.

The name of the circuit is determined by its type and type, for example, a hydraulic circuit diagram, a functional electrical circuit, etc.
The scheme cipher, which is part of its designation, consists of a letter that determines the type of scheme and a number that determines its type.
For example, a hydraulic circuit diagram has the code G3, an electrical structural diagram - E1.

For a product that contains elements different types, a combined scheme can be developed containing elements and links of different types. The combined scheme is indicated by the letter "C", and its name is determined by the combined types and type.
For example: hydrokinematic schematic diagram.

When drawing up diagrams, the following terms are used:

Circuit element - a component of the circuit that performs a specific function (purpose) in the product, which cannot be divided into parts that have an independent functional purpose.
For example, pump, coupler, capacitor, resistor, etc.

Device - a set of elements representing one design, for example, a ratchet mechanism, a printed circuit board, a cabinet.

Functional group- a set of elements that perform a specific function in the product and are not combined into one design.

Functional part - an element, equipment or functional group.

Relationship lines - a line segment on the diagram showing the relationship between the functional parts of the product.

When executing the scheme, the scales are not respected.
The actual spatial arrangement of the component parts of the product may not be taken into account in the diagram or be taken into account approximately.
The elements that make up the product are depicted on the diagrams, as a rule, in the form of conventional graphic symbols established by the standards of the Unified System design documentation (ESKD).
The connection between the circuit elements is shown by interconnection lines, which conditionally represent communications (pipelines, wires, cables, etc.) and kinematic connections (for example, shafts).
Symbols for elements general use on the diagrams sets

The diagrams should have the least number of breaks and intersections of communication lines, depicted by horizontal and vertical sections.
Schemes should be compact, but without sacrificing clarity and readability.

The elements that make up a separate device can be marked on the diagrams with dash-dotted thin lines indicating this device.
On a diagram of one type, it is allowed to depict elements of diagrams of other types that directly affect the operation of the product. These elements and their connections are also depicted by thin dash-dotted lines.

The scheme is assigned the designation of the product, the action of which is displayed on the scheme. After this designation, the scheme code is written. The name of the scheme is indicated in the main inscription after the name of the product.

Hydraulic and pneumatic circuit diagrams

The rules for the implementation of hydraulic and pneumatic circuits are established by GOST 2.704-76.
Conditional graphic designations of the elements used in these schemes are performed according to GOST 2.780-96, GOST 2.781-96 and GOST 2.784-96.
Each element or device included in the product and shown in the diagram has a reference designation consisting of a capital letter of the Russian alphabet and a number.
Letters and numbers are performed in one standard font size.

The letter designation consists of one or two letters: initial or characteristic in the name of the element. For example, a tank - B, a check valve - KO, etc.
The table of letter designations is placed in the obligatory appendix to GOST 2.704-76- "Rules for the implementation of hydraulic and pneumatic circuits."
For example, a hydraulic tank - B, a hydro (pneumatic) valve - K, a hydro (pneumatic) safety valve - KP, a filter - F, a pump - N, etc.

Sequence number included in digital designation element is assigned from one within a group of identical elements with the same letter designations.
For example, Filter - F1, F2, etc.
Ordinal numbers are usually indicated depending on the location of the elements on the diagram - from top to bottom and from left to right. The positional designation is applied on the diagram next to, to the right or above the conditional graphic representation of the element.
Element data is recorded in a standard element list table above the title block. If the entire list table does not fit above the main block of the scheme (many elements), then it is performed on a separate sheet of the format A4.

Elements and devices are depicted on the diagrams, as a rule, in their original position. For example, springs are shown in a pre-compressed state, a check valve is shown in a closed position, etc.

Communication lines (pipelines) on the diagrams are indicated by serial numbers, starting from one, which are placed on the diagram near the ends of the image of these lines. On communication lines, it is allowed to indicate the direction of the flow of the working medium (liquid, air) in the form of triangles. If the communication line is an internal channel in any element, then the serial number of the communication line through a dot is preceded by the number of this element.

The elements in the diagram are numbered. The numbers are arranged in order, starting from one, in the direction of the flow of liquid or air. An example of numbering is shown in fig. one, a.

Rice. 1Numbering of elements in the circuit diagram

Identical elements are assigned a common serial number, after which the serial number of this element is placed in brackets (Fig. 1, b). Numbers are put down on the shelves of leader lines.

Communication lines (pipelines) are also numbered. Serial numbers are assigned to pipelines after numbers are given to all elements in the scheme. Pipelines are also numbered in the direction of the flow of liquid or air (Fig. 2). If the pipeline is made in the form of drilling or a channel inside the device, then the number of this device is put before the number of such a communication line through a dot (for example, number 4.10 in Fig. 2). The pipeline number is put down near the leader lines, but unlike the element number, without shelves (see Fig. 2).

Rice. 2 . Line numbering

On fig. 2, as an example, a hydraulic circuit diagram is given, drawn up in accordance with the rules set forth.

It should be noted that on circuit diagrams along with conventional graphic symbols, elements and devices are allowed to be depicted in the form of schematic sections. Such a section is contained in the diagram shown in Fig.3.

Fig.3 . Schematic hydraulic diagram

Elements of the scheme and pipelines, which are assigned numbers, are recorded in the list of elements.

Item List is a table filled from top to bottom. It contains the following columns: reference designation, designation, name, quantity, note.

Identical elements with a common number are written in one line. This line contains the number of the initial and finite element The list of elements is placed on the first sheet of the diagram or performed in the form of subsequent sheets. In diagrams where the number of elements is small, the names, designations and technical data are indicated on the shelves of leader lines.

Symbols in hydraulic and pneumatic circuits.

For hydraulic circuits, in addition to the above conditions and designations, the following symbols and signs apply:

	Working line.
	control line.
	Drain line.
	Flexible line.
	Electric wire.
	Inside the interrupted line, the instruments are built in one unit.
	Shaft, lever, rod, piston rod.
	Connection of lines.
	Crossing lines.
	Direction of oil flow in the hydraulic circuit.
	Direction of air flow in a pneumatic circuit.
	Direction.
	Direction of rotation.
	Direction of flow in the valve. The perpendicular shows the lateral movement of the arrow.
	Adjustment indication.
	Spring.
	Adjustable spring.

Pumps and compressors . Symbols on hydraulic diagrams.

Pressure control . Pressure controls. Conventional designations.

Designation various kinds hydraulic pressure control valves on hydraulic diagrams. Designation of hydraulic motors.

Valves. Designation of valves on hydraulic diagrams.

	The valve is indicated by a square or series of squares, with each square indicating one valve operating position.
Directional control valves (e.g. boom control)
	The lines are connected to the square of the neutral position. Marking holes in the valves: P = pressure from the pump T - in tank A, B, C... - operating lines X,YZ... - control pressure a,b.c... - electrical control connections.
	One way to flow.
	Two paths for flow.
	One path for flow, two connections closed.
	Two paths for flow, one connection closed.
AT the following examples the first digit indicates the number of connections. The second digit indicates the number of working positions.
	3/2 control valve; control by pressure from both sides.
	4/3 control valve; lever control, spring return.
	6/3 control valve
	Shut-off valve (ball valve).
Pressure valves.
	Pressure limiting valve. The valve opens a flow path to the tank or to air when the valve inlet pressure exceeds the closing pressure. (Hydraulic on the left, pneumatic on the right).
	Pressure reducing valve, no pressure release. When the inlet pressure changes, the outlet pressure remains the same. But the inlet pressure by reduction must be higher than the outlet pressure.

In addition, the following symbols are used in hydraulic and pneumatic circuits (Table 2):

1 - general designation of an unregulated pump without indicating the type and type;

2 - general designation of an adjustable pump without specifying the type and type;

3 - vane pump (rotary vane) double-acting unregulated types G12-2, 714-2;

INTERSTATE STANDARD

UNIFIED SYSTEM OF DESIGN DOCUMENTATION

CONDITIONAL GRAPHIC SYMBOLS.

HYDRAULIC AND PNEUMATIC MACHINES

GOST 2.782-96

INTERSTATE COUNCIL FOR STANDARDIZATION,
METROLOGY AND CERTIFICATION

Minsk

PREFACE.

1. DEVELOPED by the Research and Design Institute of Industrial Hydraulic Drives and Hydroautomatics (NIIGidroprivod), the All-Russian Research Institute for Standardization and Certification in Mechanical Engineering (VNIINMASH).

INTRODUCED by Gosstandart of Russia.

2. ADOPTED by the Interstate Council for Standardization, Metrology and Certification (Minutes No. 10 of October 4, 1996).

State name	Name of the national standardization body
The Republic of Azerbaijan	Azgosstandart
Republic of Armenia	Armstate standard
Republic of Belarus	Belstandard
The Republic of Kazakhstan	State Standard of the Republic of Kazakhstan
Kyrgyz Republic	Kyrgyzstandart
The Republic of Moldova	Moldovastandard
Russian Federation	Gosstandart of Russia
The Republic of Tajikistan	Tajik state center for standardization, metrology and certification
Turkmenistan	Turkmenglavstate inspection
	State Standard of Ukraine

3. This standard complies with ISO 1219-91 “Hydraulic drive, pneumatic drive and devices. Conditional graphic designations and schemes. Part 1. Symbols for graphic designations" in terms of hydraulic and pneumatic machines.

4. Decree of the State Committee Russian Federation on standardization, metrology and certification dated April 7, 1997 No. 123 interstate standard GOST 2.782-96 was put into effect directly as state standard Russian Federation since January 1, 1998

5. REPLACE GOST 2.782-68.

GOST 2.782-96

INTERSTATE STANDARD

Unified system of design documentation. CONDITIONAL GRAPHIC SYMBOLS. MACHINES HYDRAULIC AND PNEUMATIC. Unified system for design documentation. Graphic designs. Hydraulic and pneumatic machines.

Introduction date 1998-01-01

1 AREA OF USE.

This standard establishes the conventional graphic symbols for hydraulic and pneumatic machines (pumps, compressors, motors, cylinders, rotary motors, converters, displacers) in diagrams and drawings of all industries.

2. REGULATORY REFERENCES.

GOST 17398-72 Pumps. Terms and Definitions.

GOST 17752-81 Volumetric hydraulic drive and pneumatic drive. Terms and Definitions.

GOST 28567-90 Compressors. Terms and Definitions.

3. DEFINITIONS.

This standard uses the terms according to GOST 17752, GOST 17398 and GOST 28567.

4. MAIN PROVISIONS.

4.1. Designations reflect the purpose (action), the way the devices work and external connections.

4.2. The designations do not show the actual design of the device.

4.3. The letters used in the symbols are only alphabetic symbols and do not represent parameters or parameter values.

4.4. Unless otherwise specified, symbols may be drawn in any position, as long as their meaning is not distorted.

4.5. The size of symbols is not set by the standard.

4.6. The designations built according to functional features must correspond to those given in Table 1.

If it is necessary to reflect the principle of operation, then the notation given in.

4.7. Rules and examples for the designation of the relationship between the direction of rotation, the direction of flow of the medium and the position of the control device for pumps and motors are given in and.

Table 1

Name	Designation
1. The pump is unregulated: With irreversible flow
Reverse flow
2. Pump adjustable: With irreversible flow
Reverse flow
3. Pump adjustable with manual control and one direction of rotation
4. Single direction pressure regulated pump with adjustable spring and drain (see and )
5. Dosing pump
6. Multi-outlet pump (for example, a three-way variable pump with one plugged outlet)
7. Hydraulic motor unregulated: With irreversible flow
Reverse flow
8. Adjustable hydraulic motor: Irreversible flow, unspecified control mechanism, external drain, one direction of rotation and two shaft ends
9. Rotary hydraulic motor
10. Compressor
11. Pneumomotor unregulated: With irreversible flow
Reverse flow
12. Adjustable pneumatic motor: With irreversible flow
Reverse flow
13. Rotary air motor
14. Pump-motor unregulated:
With any flow direction
15. Pump-motor adjustable: With the same direction of flow
With reverse flow direction
With any direction of flow, with manual control, external drain and two directions of rotation
16. Adjustable pump-motor, with two directions of rotation, spring centering of zero working volume, external control and drainage (signal n causes movement in the direction N) (mass media )
17. Volumetric hydraulic transmission: With fixed pump and motor, one direction of flow and one direction of rotation
Variable pump, flow reversible, bi-directional, variable speed
With fixed pump and one direction of rotation
18. Single acting cylinder: Piston without specifying the method of return of the rod, pneumatic
Piston with spring return, pneumatic
Piston with spring extension, hydraulic
Plunger
Telescopic with one-way extension, pneumatic
19. Double acting cylinder: Single rod, hydraulic
Double-acting, pneumatic
Telescopic with one-way extension, hydraulic
Telescopic with double-sided extension
20. Differential cylinder (the ratio of the areas of the piston from the side of the rod and non-rod cavities is of paramount importance)
21. Double-acting cylinder with the supply of the working medium through the rod: With unilateral stem
With double ended stem
22. Double-acting cylinder with constant braking at the end of the stroke: Piston side
From two sides
23. Double-acting cylinder with adjustable end-of-stroke braking: Piston side
On both sides and 2:1 area ratio Note - If necessary, the ratio of the annular area of ​​the piston to the area of ​​the piston (area ratio) can be given above the piston symbol.
24. Two-chamber double-acting cylinder
25. Diaphragm cylinder: Single acting
Double acting
26. Pneumohydraulic displacer with separator: Translational
rotational
27. Translational transducer:
28. Rotary transducer: With one kind of working environment
With two kinds of working environment
29. Cylinder with built-in mechanical locks

Name	Designation
1. Manual pump
2. Gear pump
3. Screw pump
4. Vane pump
5. Radial piston pump
6. Axial piston pump
7. Crank pump
8. Centrifugal vane pump
9. Jet pump: General designation
With liquid external flow
With gas external flow
10. Fan: Centrifugal

APPENDIX A
(recommended)
RULES FOR DESIGNATION OF ROTATION DIRECTION DEPENDENCE ON WORKING FLOW DIRECTION AND CONTROL DEVICE POSITION FOR HYDRO- AND PNEUMATIC MACHINES.

A.1. The direction of rotation of the shaft is shown by a concentric arrow around the main designation of the machine from the power supply element to the power output element. For devices with two directions of rotation, only one arbitrarily chosen direction is shown. For double shaft devices, the direction is shown at one end of the shaft.

A.2. For pumps, the arrow starts on the drive shaft and ends with a point on the outlet flow line.

A.3. For motors, the arrow starts at the inlet flow line and ends with the point of the arrow at the output shaft.

A.4. For motor pumps according to A.2 and A.3.

A.5. If necessary, the corresponding designation of the position of the control device is shown near the tip of the concentric arrow.

A.6. If the control characteristics are different for the two directions of rotation, information is shown for both directions.

A.7. A line showing the positions of the control device and designations of positions (for example, M - Æ - N) is applied perpendicular to the control arrow. The sign Æ denotes the position of the zero working volume, the letters M and N indicate the extreme positions of the control device for the maximum displacement. It is preferable to use the same designations that are printed on the body of the device.

The point of intersection of the arrow showing regulation and perpendicular to the line indicates the position "in stock" (Figure 1).

Picture 1.

APPENDIX B
(recommended)
EXAMPLES OF DESIGNATION OF ROTATION DIRECTION DEPENDENCE ON WORKING FLOW DIRECTION AND CONTROL DEVICE POSITIONS FOR HYDRO AND PNEUMATIC MACHINES.

Table B.1

Name	Designation
1. Single-functional device (motor). The hydraulic motor is unregulated, with one direction of rotation.
2. Single-functional device (machine). The hydraulic machine is unregulated, with two directions of rotation.
3. Single-functional device (pump). The hydraulic pump is adjustable (with a change in working volume in one line), with one direction of rotation. The designation of the position of the control device can be omitted, it is shown in the figure for clarity only.
4. Single-functional device (motor). The hydraulic motor is adjustable (with a change in working volume in one direction), with two directions of rotation. One direction of rotation is shown, related to the direction of flow.
5. Single-functional device (machine). The hydraulic machine is adjustable (with a change in working volume in both directions), with one direction of rotation. The direction of rotation and the corresponding position of the control device are shown in relation to the direction of flow.
6. Single-functional device (machine). The hydraulic machine is adjustable (with a change in the working volume in both directions), with two directions of rotation. Shown is one direction of rotation and the corresponding position of the control device associated with the direction of flow.
7. Pump-motor. The pump-motor is unregulated with two directions of rotation.
8. Pump-motor. The pump-motor is adjustable (with a change in working volume in one direction), with two directions of rotation. One direction of rotation is shown, related to the direction of flow, when operating in pump mode.
9. Pump-motor. The pump-motor is adjustable (with a change in the working volume in both directions), with one direction of rotation. Shows the direction of rotation and the corresponding position of the control device, related to the direction of flow, when operating in pump mode.
10. Pump-motor. Pump-motor adjustable (with the use of a working volume in both directions, with two directions of rotation. Shown is one direction of rotation and the corresponding position of the control device associated with the direction of flow when operating in pump mode.
Motor with two directions of rotation: adjustable (with change of displacement in one line) in one direction of rotation, non-adjustable in the other direction of rotation. Both possibilities are shown.

Keywords: conditional graphic symbols, hydraulic and pneumatic machines

INTERSTATE STANDARD

UNIFIED SYSTEM OF DESIGN DOCUMENTATION

CONDITIONAL GRAPHIC SYMBOLS.

HYDRAULIC AND PNEUMATIC MACHINES

GOST 2.782-96

INTERSTATE COUNCIL FOR STANDARDIZATION,
METROLOGY AND CERTIFICATION

PREFACE.

1. DEVELOPED by the Research and Design Institute of Industrial Hydraulic Drives and Hydroautomatics (NIIGidroprivod), All-Russian Research Institute for Standardization and Certification in Mechanical Engineering (VNIINMASH). INTRODUCED by the State Standard of Russia.2. ADOPTED by the Interstate Council for Standardization, Metrology and Certification (Minutes No. 10 dated October 4, 1996). The following voted for the adoption:

State name	Name of the national standardization body
The Republic of Azerbaijan	Azgosstandart
Republic of Armenia	Armstate standard
Republic of Belarus	Belstandard
The Republic of Kazakhstan	State Standard of the Republic of Kazakhstan
Kyrgyz Republic	Kyrgyzstandart
The Republic of Moldova	Moldovastandard
Russian Federation	Gosstandart of Russia
The Republic of Tajikistan	Tajik State Center for Standardization, Metrology and Certification
Turkmenistan	Turkmenglavstate inspection
Ukraine	State Standard of Ukraine

3. This standard complies with ISO 1219-91 “Hydraulic drive, pneumatic drive and devices. Conditional graphic designations and schemes. Part 1. Symbols graphic designations" in terms of hydraulic and pneumatic machines.4. By the Decree of the State Committee of the Russian Federation for Standardization, Metrology and Certification dated April 7, 1997 No. 123, the interstate standard GOST 2.782-96 was put into effect directly as the state standard of the Russian Federation from January 1, 1998. 5. INSTEAD OF GOST 2.782-68.6. REPUBLICATION. January 1998

1 area of ​​use. 2 2. Regulatory references. 2 3. Definitions. 2 4. Basic provisions. 2 Annex A Rules for indicating the dependence of the direction of rotation on the direction of the flow of the working medium and the position of the control device for hydraulic and pneumatic machines. eight Annex B Examples of designation of the dependence of the direction of rotation on the direction of the flow of the working medium and the positions of the control device for hydraulic and pneumatic machines. eight

GOST 2.782-96

INTERSTATE STANDARD

Unified system of design documentation. CONDITIONAL GRAPHIC SYMBOLS. MACHINES HYDRAULIC AND PNEUMATIC. Unified system for design documentation. Graphic designs. Hydraulic and pneumatic machines.

Introduction date 1998-01-01

1 AREA OF USE.

This standard establishes the conventional graphic symbols for hydraulic and pneumatic machines (pumps, compressors, motors, cylinders, rotary motors, converters, displacers) in diagrams and drawings of all industries.

2. REGULATORY REFERENCES.

This standard uses references to the following standards: GOST 17398-72 Pumps. Terms and Definitions. GOST 17752-81 Volumetric hydraulic drive and pneumatic drive. Terms and definitions. GOST 28567-90 Compressors. Terms and Definitions.

3. DEFINITIONS.

This standard uses the terms according to GOST 17752, GOST 17398 and GOST 28567.

4. MAIN PROVISIONS.

4.1. Designations reflect the purpose (action), the way the devices work and external connections. 4.2. The designations do not show the actual design of the device.4.3. The letters used in the designations are only alphabetic designations and do not give an idea of ​​the parameters or parameter values.4.4. Unless otherwise specified, symbols may be drawn in any arrangement, as long as their meaning is not distorted. 4.5. The standard does not establish the sizes of symbols. 4.6. Designations built according to functional features should correspond to those given in table 1. If it is necessary to reflect the principle of operation, then the designations given in table 2.4.7 are used. Rules and examples of designations for the relationship between the direction of rotation, the direction of flow of the medium and the position of the control device for pumps and motors are given in appendices A and B.

Table 1

Name	Designation
1. The pump is unregulated: - with non-reversible flow
- with reverse flow
2. Adjustable pump: - with non-reversible flow
- with reverse flow
3. Pump adjustable with manual control and one direction of rotation
4. Single direction pressure regulated pump with adjustable spring and drain (see appendices A and B)
5. Dosing pump
6. Multi-outlet pump (for example, a three-way variable pump with one plugged outlet)
7. Hydraulic motor unregulated: - with non-reversible flow
- with reverse flow
8. Adjustable hydraulic motor: - with non-reversible flow, with indefinite control mechanism, external drainage, one direction of rotation and two shaft ends
9. Rotary hydraulic motor
10. Compressor
11. Non-adjustable pneumatic motor: - with non-reversible flow
- with reverse flow
12. Adjustable pneumatic motor: - with non-reversible flow
- with reverse flow
13. Rotary air motor
14. Pump-motor unregulated: - with the same direction of flow
- with any flow direction
15. Adjustable motor pump: - with the same flow direction
- with reverse flow direction
- with any direction of flow, with manual control, external drain and two directions of rotation
16. Adjustable pump-motor, with two directions of rotation, spring centering of zero working volume, external control and drainage (signal n causes movement in the direction N) (see appendices A and B)
17. Volumetric hydraulic transmission: - with fixed pump and motor, with one direction of flow and one direction of rotation
- with adjustable pump, with reverse flow, with two directions of rotation with variable speed
- with fixed pump and one direction of rotation
18. Single-acting cylinder: - piston without specifying the method of return of the rod, pneumatic
- piston with spring return, pneumatic
- piston with rod extension by a spring, hydraulic
- plunger
- telescopic with one-sided extension, pneumatic
19. Double-acting cylinder: - with single-acting rod, hydraulic
- double-acting, pneumatic
- telescopic with one-sided extension, hydraulic
- telescopic with double-sided extension
20. Differential cylinder (the ratio of the areas of the piston from the side of the rod and non-rod cavities is of paramount importance)
21. Double-acting cylinder with a supply of the working medium through the rod: - with a single-sided rod
- with a double-sided stem
22. Double-acting cylinder with constant braking at the end of the stroke: - from the piston side
- on both sides
23. Double-acting cylinder with adjustable braking at the end of the stroke: - from the piston side
- on both sides and an area ratio of 2:1
24. Two-chamber double-acting cylinder
25. Diaphragm cylinder: - single-acting
- double acting
26. Pneumohydraulic displacer with separator: - translational
- rotational
27. Translational transducer: - with one kind of working environment
28. Rotary transducer: - with one kind of working environment
- with two kinds of working environment
29. Cylinder with built-in mechanical locks

table 2

Name	Designation
1. Manual pump
2. Gear pump
3. Screw pump
4. Vane pump
5. Radial piston pump
6. Axial piston pump
7. Crank pump
8. Centrifugal vane pump
9. Jet pump: General designation
With liquid external flow
With gas external flow
10. Fan: Centrifugal

APPENDIX A
(recommended)
RULES FOR DESIGNATION OF ROTATION DIRECTION DEPENDENCE ON WORKING FLOW DIRECTION AND CONTROL DEVICE POSITION FOR HYDRO- AND PNEUMATIC MACHINES.

A.1. The direction of rotation of the shaft is shown by a concentric arrow around the main designation of the machine from the power supply element to the power output element. For devices with two directions of rotation, only one arbitrarily chosen direction is shown. For double shaft devices, the direction is shown at one end of the shaft. A.2. For pumps, the arrow starts on the drive shaft and ends with a point on the outlet flow line. A.3. For motors, the arrow starts at the inlet flow line and ends with the point of the arrow at the output shaft. A.4. For motor pumps according to A.2 and A.3.A.5. If necessary, the appropriate designation of the position of the control device is shown near the tip of the concentric arrow. A.6. If the control characteristics are different for the two directions of rotation, information is shown for both directions. A.7. A line showing the positions of the control device and position symbols (for example, M - Æ - N) is applied perpendicular to the control arrow. The sign Æ indicates the position of the zero displacement, the letters M and N indicate the extreme positions of the control device for the maximum displacement. It is preferable to use the same designations that are printed on the body of the device. The point of intersection of the arrow showing the regulation and perpendicular to the line indicates the position "in stock" (Figure 1).

Picture 1.

APPENDIX B
(recommended)
EXAMPLES OF DESIGNATION OF ROTATION DIRECTION DEPENDENCE ON WORKING FLOW DIRECTION AND CONTROL DEVICE POSITIONS FOR HYDRO AND PNEUMATIC MACHINES.

Table B.1

Name	Designation
1. Single-functional device (motor). The hydraulic motor is unregulated, with one direction of rotation.
2. Single-functional device (machine). The hydraulic machine is unregulated, with two directions of rotation. One direction of rotation is shown, related to the direction of flow.
3. Single-functional device (pump). The hydraulic pump is adjustable (with a change in working volume in one line), with one direction of rotation. The designation of the position of the control device can be omitted, it is shown in the figure for clarity only.
4. Single-functional device (motor). The hydraulic motor is adjustable (with a change in working volume in one direction), with two directions of rotation. One direction of rotation is shown, related to the direction of flow.
5. Single-functional device (machine). The hydraulic machine is adjustable (with a change in working volume in both directions), with one direction of rotation. The direction of rotation and the corresponding position of the control device are shown in relation to the direction of flow.
6. Single-functional device (machine). The hydraulic machine is adjustable (with a change in the working volume in both directions), with two directions of rotation. Shown is one direction of rotation and the corresponding position of the control device associated with the direction of flow.
7. Pump-motor. The pump-motor is unregulated with two directions of rotation.
8. Pump-motor. The pump-motor is adjustable (with a change in working volume in one direction), with two directions of rotation. One direction of rotation is shown, related to the direction of flow, when operating in pump mode.
9. Pump-motor. The pump-motor is adjustable (with a change in the working volume in both directions), with one direction of rotation. Shows the direction of rotation and the corresponding position of the control device, related to the direction of flow, when operating in pump mode.
10. Pump-motor. The pump-motor is adjustable (using a displacement in both directions, with two directions of rotation. One direction of rotation and the corresponding position of the control device associated with the direction of flow are shown when operating in pump mode.
11. Motor. Motor with two directions of rotation: adjustable (with change of displacement in one line) in one direction of rotation, non-adjustable in the other direction of rotation. Both possibilities are shown.

Keywords: conditional graphic symbols, hydraulic and pneumatic machines