How to choose a good electric ball valve

Publish Time:

2021-12-22

In the current market economy, simply specifying the specifications, category, and pressure of electric ball valves to meet procurement requirements is insufficient. To enhance product competitiveness, manufacturers of electric ball valves have made various innovations based on the concept of unified design, resulting in their own enterprise standards and product individuality. Therefore, it is necessary to specify detailed technical requirements when purchasing electric ball valves and reach a consensus with the manufacturer. Including this as an attachment to the electric ball valve purchase contract is essential.

In the current market economy, simply specifying the specifications, category, and pressure of electric ball valves to meet procurement requirements is insufficient. To enhance product competitiveness, electric ball valve manufacturers have made various innovations based on the concept of unified design, resulting in their own enterprise standards and product individuality. Therefore, it is necessary to create detailed technical requirements when selecting electric ball valves and reach a consensus with the manufacturer. This should be included as an attachment to the electric ball valve procurement contract.

I. General Requirements

1.1 The specifications and categories of the electric ball valve should comply with the requirements of the pipeline design documents.

1.2 The model of the electric ball valve should indicate the national standard number. If it is an enterprise standard, the relevant model description should be provided.

1.3 The working pressure of the electric ball valve should be ≥ the working pressure of the pipeline. Without affecting the price, the working pressure of the electric ball valve should be greater than the actual working pressure of the pipeline; any side of the electric ball valve should be able to withstand 1.1 times the working pressure without leakage when closed; when the electric ball valve is opened, the valve body should be able to withstand twice the working pressure of the electric ball valve.

1.4 The manufacturing standard of the electric ball valve should indicate the national standard number used. If it is an enterprise standard, the enterprise document should be attached to the procurement contract.

2. Variable Speed Transmission Box

2.1 The material and internal and external anti-corrosion requirements of the box are consistent with the valve body principle.

2.2 The box should have sealing measures, and after assembly, the box can withstand immersion in a 3-meter water column.

2.3 The opening and closing limit device on the box, the adjusting nut should be inside or outside the box, but requires a special tool to operate.

2.4 The transmission structure design is reasonable. When opening and closing, it can only drive the valve stem to rotate, without causing up and down movement, the transmission parts mesh normally, and will not cause separation and slippage during load opening and closing.

2.5 The variable speed transmission box and the valve stem seal cannot be connected as a leak-proof whole; otherwise, reliable leak-proof measures should be taken.

2.6 There are no sundries in the box, and the gear meshing parts should be protected with grease.

3. Electric Ball Valve Quality Standards

3.1 The valve body material should mainly be ductile iron, and the grade and actual physicochemical test data of the cast iron should be indicated.

3.2 Valve stem material, preferably stainless steel valve stem (2CR13), large-diameter electric ball valves should also be stainless steel embedded valve stems.

3.3 Nut material uses cast aluminum brass or cast aluminum bronze, with hardness and strength greater than the valve stem.

3.4 The valve stem bushing material should have a hardness and strength no greater than that of the valve stem, and should not form electrochemical corrosion with the valve stem and valve body when immersed in water.

3.5 Sealing surface material: ① Electric ball valves have different types, sealing methods, and material requirements; ② Ordinary wedge gate valves, copper ring materials, fixing methods, and grinding methods are described; ③ Soft seal gate valves, valve plate lining rubber material physicochemical and hygiene test data; ④ Butterfly valves should indicate the sealing surface material of the valve body and the butterfly plate sealing surface material on the valve body; their physicochemical test data, especially the hygiene requirements, chemical properties, and wear resistance of rubber; usually used for nitrile rubber and ethylene propylene rubber, and the use of reclaimed rubber is strictly prohibited.

3.6 Valve stem packing: ① Since electric ball valves in pipe networks are usually not frequently opened and closed, the packing is required not to move for several years, the packing does not age, and the sealing effect is maintained for a long time; ② The valve stem packing should also be frequently opened and closed. When closed, the sealing effect is good; ③ In view of the above requirements, the valve stem packing should not be replaced for more than ten years; ④ If the packing needs to be replaced, the electric ball valve design should consider the following measures:

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