1. General requirements

1.1 pneumatic valve specifications and category, should comply with the requirements of pipeline design documents.

1.2 the pneumatic valve type shall be marked the gb Numbers required basis. If the enterprise standard, should indicate the type of related instructions.

1.3 pneumatic valve work pressure, request the working pressure of the frequency pipe, no impact on the price, under the premise of valve can withstand the pressure should be greater than the work of actual work pressure pipe; Pneumatic valve close condition of any side should be able to withstand the pressure difference 1.1 times the valve leakage and work; The valve opens situation, the body should be able to take two times the pressure of the valve work requirements.

1.4 pneumatic valve manufacturing standard, that should be the basis for gb Numbers, if the enterprise standard, purchasing contract should be attached on enterprise file.

2. Solenoid standard quality

2.1 body materials, should be with nodular cast iron is given priority to, and indicate the brand and the physical chemistry of cast iron actual test data.

2.2 stem material, and strive to stainless steel valve stem (2 CR13), large diameter valve should also be embedded bag the valve stem of the stainless steel.

2.3 nut material, using aluminum brass or aluminum bronze, and the hardness and strength are greater than the valve stem.

2.4 stem bushing material, its hardness and strength are shall not be more than the valve stem, and in the soaking water condition and stem, valve body do not form electrochemical corrosion.

2.5 the sealing surface material

(1) pneumatic valve category is differ, sealing material requirements and different way;

(2) the ordinary wedge type gate, copper ring material, fixed way, grinding way all should explain;

(3) soft-sealing gate valve, the valve plate rubber lining material of physical chemistry and hygiene inspection data;

(4) the butterfly valve should be marked on the body sealing butterfly plate material and the sealing surface material; Their physical and chemical testing data, especially rubber health requirements, anti-aging properties, wear-resisting performance; Usually by butadiene acrylonitrile rubber and epdm, mixed with reclaimed rubber is strictly prohibited.

2.6 valve spindle packing

(1) the pneumatic valve due to pipe network, is usually not opening and closing of the frequent, packing requirements in a number of years not activities, packing also don't aging, maintained for a long time sealing effect;

(2) the valve spindle packing should also be under frequent opening and closing, sealing effect good sex;

(3) in the above requirements and valve spindle packing life don't change or to ten years not to change;

(4) if the need to change the packing, pneumatic valve design should consider to have the condition of the water pressure replacement measures.

3. Variable speed transmission box

3.1 the material and internal &external anti-corrosion requirements and body principles.

The seal measures should be 3.2, after the assembly can bear 3 m of water status soak.

3.3 the opening and closing of the spacing device, the control should be in the cabinet or nuts in the box, but need special tools to work.

3.4 the transmission structure reasonable design, open only drive shaft rotation when valve, don't make the leap up and down to move, transmission parts bite measurable, do not produce loading when opening and closing separation skid.

The variable speed drive with the 3.5 shaft seal shall not linked to the whole without leakage, or should have reliable control measures of leakage.

3.6 the cabinet without sundry, gear bite site should have a grease protection.