GB/T 1222021980- General purpose valves - Marking

GB/T 1222121989- Flanged metal valves - Structural length

GB/T 122221989- Connections of multi turn valve drive devices

GB/T 1222521989- General purpose valves - Technical specifications for copper alloy castings

GB/T 1222621989- General purpose valves - Technical specifications for grey cast iron parts

GB/T 1222721989- General purpose valves - Technical specifications for ductile iron castings

GB/T 1222921989- General purpose valves - Technical specifications for carbon steel castings

GB/T 1223021989- General purpose valves - Technical specifications for austenitic steel castings

GB/T 1223221989- General purpose valves - Flanged iron gate valves

GB/T 1223321989- General purpose valves - Iron globe valves and lift check valves

GB/T 1223421989- General purpose valves - Steel gate valves with flange and butt welded connections

GB/T 1223521989- General purpose valves - flanged steel globe valves and lift check valves

GB/T 1223621989- General purpose valves - Steel swing check valves

GB/T 1223721989- General purpose valves - Steel ball valves with flange and butt welded connections

GB/T 1223821989- General purpose valves - Flanged and clamped butterfly valves

GB/T 1224321989- Spring direct load safety valve

GB/T 1224421989- Pressure reducing valves - General requirements

GB/T 1393221992- General purpose valves - Iron swing check valves

GB/T 1417321993- Flat Steel Gates - Technical Conditions

GB/T 1518521994- Iron and Copper Ball Valves

GB/T 846421998- Internal Threaded Valves for Plumbing

JB 30821975 Valve - Model Compilation Method

JB/T 529921998- Hydraulic Control Check Butterfly Valve

JB/T 792721999- Appearance Quality Requirements for Valve Cast Steel Parts

JB/T 792821999- General Valves - Supply Requirements

JB/T 852721997- Metal Sealed Butterfly Valve

JB/T 852821997- Technical Conditions for Electric Devices of Ordinary Valves

JB/T 853121997- Technical Conditions for Valve Manual Devices

JB/T 86912998- Clamp on Knife Gate Valve

When mass manufacturing a certain specification of valve, authoritative institutions should be commissioned to conduct the following performance tests:

1. The opening and closing torque of the valve under working pressure conditions.

2. The continuous opening and closing times that can ensure the valve is tightly closed under working pressure conditions.

3. Detection of flow resistance coefficient of valves under pipeline water delivery conditions.

Valves should undergo the following tests before leaving the factory:

1. When the valve is in the open position, the valve body should withstand an internal pressure test of twice the working pressure value of the valve.

2. When the valve is closed, both sides can withstand 1.1 times the working pressure value of the valve without leakage; But for metal sealed butterfly valves, the leakage value should not exceed the relevant requirements.

Internal and external anti-corrosion of valves:

1. The inside and outside of the valve body (including the gearbox) should first be shot blasted, sandblasted, and rust removed, striving for electrostatic spraying of powder non-toxic epoxy resin with a thickness of at least 0.3mm. When it is difficult to electrostatically spray non-toxic epoxy resin on extra large valves, similar non-toxic epoxy paint should also be brushed or sprayed.

2. The interior of the valve body and various parts of the valve plate require comprehensive anti-corrosion measures. On the one hand, immersion in water will not corrode, and there will be no electrochemical corrosion between the two metals; Smooth surface on both sides reduces water resistance.

3. The hygiene requirements for anti-corrosion epoxy resin or paint inside the valve body should be accompanied by testing reports from relevant authoritative authorities. The chemical and physical properties should also meet relevant requirements.

Valve appearance requirements:

1. The coating on the valve body should be uniform and there should be no peeling or bubbles.

2. The valve body should be kept clean and free from oil stains and other contaminants.

3. The nameplate on the valve body should be clear and legible, with the full name of the manufacturer, production time, factory time, valve specifications and models, the name and number of the valve testing standard, and the inspector number for factory inspection.

4. The valve stem handwheel should indicate the opening and closing direction of the valve, and it should be clear and concise; For one-way valves, the direction of water flow should be clearly indicated on the valve body.

Valve packaging and transportation:

1. Lightweight blocking plates should be installed on both sides of the valve for secure sealing.

2. Small and medium-sized valves should be tied with grass ropes and transported in containers.

3. Large caliber valves also come with simple wooden frame fixation packaging to prevent damage during transportation.

Valve operating mechanism

1. The opening and closing direction of the valve during operation should always be clockwise.

2. Due to the frequent manual opening and closing of valves in the pipeline network, the opening and closing speed should not be too high, even for large-diameter valves, it should be within 200-600 revolutions.

3. For the convenience of one person's opening and closing operation, the maximum opening and closing torque under pipeline pressure conditions should be 240m-m.

4. The valve opening and closing operation end should be square tenon, standardized in size, and facing the ground, so that people can directly operate it from the ground. Valves with discs are not suitable for underground pipelines.

5. If the valve is buried deep and the distance between the operating mechanism and the display panel and the ground is ≥ 15m, an extension rod facility should be installed and firmly fixed for people to observe and operate from the ground. That is to say, the opening and closing of valves in the pipeline network is not suitable for underground operations.

Display panel for valve opening and closing degree:

1. The scale line for the degree of valve opening and closing should be cast on the gearbox cover or the outer shell of the display panel after changing direction, all facing the ground. The scale line should be brushed with fluorescent powder to indicate visibility.

2. The material of the indicator disk needle can be made of stainless steel plate under good management, otherwise it is painted steel plate and aluminum sheet should not be used.

3. The indicator pin should be conspicuous and securely fixed. Once the opening and closing adjustment is accurate, it should be locked with rivets.

Valve shaft packing:

1. Due to the infrequent opening and closing of valves in the pipeline network, it is required that the packing should remain inactive for several years, and the packing should not age to maintain a long-term sealing effect.

2. The valve shaft packing should also have good sealing performance when subjected to frequent opening and closing.

3. In view of the above requirements, the valve shaft packing should be kept unchanged for life or more than ten years.

4. If the packing needs to be replaced, the valve design should consider measures to replace it under water pressure conditions.

Transmission gearbox:

1. The material of the box and the requirements for internal and external anti-corrosion are consistent with the principles of the valve body.

2. The box should have sealing measures and be able to withstand immersion in a 3-meter water column after assembly.

3. The adjustment nut of the opening and closing limit device on the box should be inside the box.

4. The transmission structure is designed reasonably, which can only drive the valve shaft to rotate during opening and closing, without causing it to move up and down. The transmission components are moderately engaged, and there is no separation slip during load opening and closing.

5. The gearbox and valve shaft seal should not be connected as a leak free whole, otherwise reliable anti leakage measures should be taken.

6. There are no impurities inside the box, and the gear meshing area should be protected with lubricating grease.

General requirements:

1. The specifications and categories of valves should comply with the requirements of the pipeline design documents.

2. The model of the valve should indicate the national standard number requirements it is based on. If it is an enterprise standard, the relevant description of the model should be indicated.

3. The working pressure of the valve should be ≥ the working pressure of the pipeline. Without affecting the price, the working pressure that the valve can withstand should be greater than the actual working pressure of the pipeline; Either side of the valve should be able to withstand 1.1 times the working pressure of the valve without leakage when it is closed; When the valve is open, the valve body should be able to withstand twice the working pressure of the valve.

4. The valve manufacturing standard should specify the national standard number it is based on. If it is an enterprise standard, the procurement contract should be accompanied by the enterprise document.

Valve component material:

1. Valve material, as gray cast iron pipes are gradually not recommended, the valve body material should be mainly ductile iron, and the brand and actual physical and chemical testing data of the casting should be indicated.

2. The valve stem material should strive for stainless steel stem (2CR13), and large-diameter valves should also have stainless steel embedded stem.

3. The nut material is made of cast aluminum brass or cast aluminum bronze, and its hardness and strength are greater than those of the valve stem.

4. The material of the valve stem liner should have a hardness and strength not greater than that of the valve stem, and should not form electrochemical corrosion with the valve stem and valve body when immersed in water.

3、 Material of sealing surface:

1. The types of valves vary, and the requirements for sealing methods and materials are also different.

2. The material, fixing method, and grinding method of the copper ring for ordinary wedge gate valves should be specified.

3. Physical, chemical, and hygiene testing data for soft sealed gate valves and valve plate lining materials.

4. Butterfly valves should indicate the sealing surface material on the valve body and the sealing surface material on the butterfly plate; Their physical and chemical test data, especially the sanitary requirements, anti-aging performance and wear resistance of rubber, are usually made of butadiene rubber and EPDM rubber, and recycled rubber is strictly prohibited.