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Valve standard

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national standard PN25
Valve Specification flange thickness bolt quantity
DN100 28mm M20 * 85 8
DN125 30mm M22 * 85 8
DN150 30mm M22 * 85 8
DN200 32mm M22 * 90 12
DN250 34mm M27 * 100 12 Where are the valve standards? There are valve standards here, but I still can’t find the valve standards, Ask everywhere. If you have any, tell me the website of valve standards. Valve standards are very difficult to find. I really need valve standards now. If anyone can find valve standards, tell me the website of valve standards. Thank you for telling me the valve standards. It’s not easy to find the valve standards. There are valve standards here. There are valve standards here. I still can’t find the valve standards, Ask everywhere. If you have any, tell me the website of the valve standard. The valve standard is very difficult to find. I really need the valve standard now. If anyone can find the valve standard, tell me the website of the valve standard. Thank you for telling me the valve standard. It’s not easy to find the valve standard. Thank you

JB /T 308-2004 valve model preparation method clear version free download:
Wenku/view/

inspection standards and technical requirements for valves
1. General requirements for valves
1.1. The specification and category of valves shall meet the requirements of pipeline design documents
1.2. The model of the valve shall be indicated with the International Numbering requirements. If it is an enterprise standard, the relevant description of the model shall be indicated
1.3. The working pressure of the valve is required to be ≥ the working pressure of the pipeline. On the premise of not affecting the price, the valve can withstand
The working pressure shall be greater than the actual working pressure of the pipeline; When the valve is closed, either side shall be able to withstand 1.1 times the valve
Door working pressure value without leakage; When the valve is open, the valve body shall be able to withstand the requirements of twice the working pressure of the valve
1.4. For the valve manufacturing standard, the international number shall be stated. If it is an enterprise standard, the enterprise document shall be attached to the purchase contract

II. Valve material
2.1. Valve material. Since the gray cast iron pipe material is not recommended, the valve body material should be mainly nodular cast iron, and the brand
and the actual physical and chemical test data should be indicated
2.2. The valve stem shall be made of stainless steel (2Cr13). Large diameter valves shall also be stainless steel embedded valve stems
2.3. The nut is made of cast aluminum brass or cast aluminum bronze, and its hardness and strength are greater than that of the valve stem
2.4. The valve stem bushing is made of a material that is harder and stronger than the valve stem, and the valve stem and valve body do not form electricity when it rains in the water immersion condition
Chemical corrosion
2.5, material of sealing surface
1、 Different types of valves, different sealing methods and material requirements
2、 For ordinary wedge gate valve, the material, fixing method and grinding method of copper ring shall be described
3、 Physicochemical and hygienic test data of soft seal gate valve and valve plate rubber lining materials
4、 The butterfly valve shall be marked with the material of the sealing surface on the valve body and the material of the sealing surface on the disc plate; Their physicochemical test data
In particular, the hygienic requirements, anti-aging and wear resistance of rubber. NBR and EPDM are usually used
Rubber, etc. it is strictly prohibited to mix recycled rubber
2.6, valve shaft packing
first, since the valves in the pipe network are usually opened and closed infrequently, the packing is required to be inactive for several years, and the packing is not aging
to maintain the sealing effect for a long time
Second, the valve shaft packing should also bear the frequent opening and closing, and the sealing effect is good
III. in view of the above requirements, the valve shaft packing shall not be replaced for life or more than ten years
Fourth, if the packing needs to be replaced and the valve design should consider the measures of replacement under the condition of who can be there

III. gearbox
3.1. The material and internal and external anti-corrosion requirements of the box are consistent with the principles of the valve body
3.2. The box shall be provided with sealing measures. After assembly, the box can withstand the immersion of 3M water column
3.3. The adjusting nut of the opening and closing limit device on the box shall be in the box
3.4. The design of transmission structure is reasonable. When opening and closing, it can only drive the valve shaft to rotate without moving up and down.
the transmission parts are properly engaged and do not separate and slip when opening and closing with load
3.5. The seal between the variable speed transmission box and the valve shaft shall not be connected into a leak free whole
3.6. There are no sundries in the box, and the meshing part of the gear should be lubricated and protected

Fourth, the operating mechanism of the valve
4.1. The opening and closing direction of the valve during operation shall be clockwise
4.2 because the valves in the pipe network are often opened and closed manually, the number of opening and closing revolutions should not be too much, so
If it is a large-diameter valve, it should also be within 200-600 revolutions
4.3. In order to facilitate the opening and closing operation of one person, the maximum opening and closing torque is 240n * m under the working pressure of the pipeline
4.4. The opening and closing operation of the valve shall be square tenon, with standardized size and facing the ground, so that
People operate directly from the ground. Valves with wheel discs are not suitable for underground pipe networks
4.5, display panel of valve opening and closing degree
1、 The scale mark of the opening and closing degree of the valve shall be cast on the gearbox cover or the display panel after changing the direction
On the shell of the, the fluorescent powder shall be applied to the ground and scale lines to show eye-catching
2、 Stainless steel plate can be used for indicating the material of dial needle under good management, otherwise it is painted
Steel plate, do not use aluminum sheet
3、 The indicator needle shall be eye-catching and firmly fixed. Once the opening and closing adjustment is accurate, it shall be locked with rivets
4.6. If the valve is buried deeply and the distance between the operating mechanism and the display panel from the ground is ≥ 1-5m, an extension rod
facility shall be set, which is firm and stable for people to observe and operate on the ground. In other words, the opening and closing operation of
valves in the pipe network is not suitable for downhole operation

5, valve performance test
5.1 when the valve is manufactured in batch with a certain specification, the following performance tests shall be entrusted to the authority:
first, the opening and closing torque of the valve under working pressure
2. Continuous opening and closing times that can ensure tight valve closure under working pressure
Third, the flow resistance coefficient of the valve under the condition of pipeline water delivery
5.2. Before leaving the factory, the valve shall be tested as follows:
first, when the valve is open, the valve body shall withstand the internal pressure test of twice the working pressure of the valve
Second, when the valve is closed, both sides bear 1.1 times the working pressure of the valve without leakage
however, the leakage of metal sealed butterfly valves shall not exceed
the relevant requirements

VI. internal and external anti-corrosion of the valve
6.1. Shot blasting and sand removal shall be carried out for the inside and outside of the valve body (including the variable speed transmission box) to strive for electrostatic powder spraying
Non toxic epoxy resin with a thickness of more than 0.3mm. Difficulty in electrostatic spraying non-toxic epoxy resin on extra large valves
Similar non-toxic epoxy paint shall also be brushed and sprayed when
6.2. The interior of the valve body and all parts of the valve plate shall be fully protected against corrosion. On the one hand, it will not rust when immersed in water There is no electrochemical corrosion between the two metals; On the other hand, the smoothness reduces the overflow resistance
6.3. The hygienic requirements for the anti-corrosion epoxy resin or paint in the valve body shall have the
test report of the corresponding authority. Chemical and physical properties shall also meet relevant requirements

VII. Valve packaging and transportation
7.1. Light blocking plates shall be set on both sides of the valve for fixation
7.2. Medium and small diameter valves should be bound with straw ropes and transported in containers
7.3. Large diameter valves are also fixed and packed with simple wooden strip frames to avoid damage during transportation

VIII. Valve factory instruction
8.1. Valve is equipment, and relevant data shall be indicated in the factory instruction:
Valve specification, model, working pressure, manufacturing standard, valve body material, valve stem material, sealing material,
Material of valve stem, material of packing, number of rotating shaft, material of operating sleeve,
Opening and closing torque under working conditions and name of manufacturer; Factory date, factory number, weight,
The hole diameter, number of holes, center hole spacing of the connecting flange, the
control size indicating the overall length, width and height in a graphical way, the flow resistance coefficient of the valve, the relevant data of the factory inspection of the valve and the precautions for installation and maintenance, etc.

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