• Follow us
Home > Exhibition > Content
How to buy high quality corrosion protection valves
Nov 24, 2016

1. General requirements

1.1 valve specifications and category shall comply with the requirements of design documents.

1.2 valve type should be indicated based on the standard number of requirements. If the enterprise standards, indicate the type of note.

1.3 valve pressure requirements above the operating pressure of the pipeline, without affecting the price of the premise, the valve can withstand working pressure should be greater than the actual working pressure of valve closing conditions on either side should be able to withstand pressure value for 1.1 times the valve without leakage; condition of valve opening, valve shall withstand twice the valve operating pressure requirements.

1.4 valve manufacturing standards, should indicate the basis of the standard number, if the enterprise standards, procurement contracts shall be attached to the enterprise documents.

2. valve standard quality

2.1 valve body material, should be mainly ductile iron, physico-chemical data and indicate the actual grades and cast iron.

2.2 stem material, to stainless steel stem (2CR13), maintenance of large diameter valves should be embedded in the package of stainless steel stem.

2.3 nut material, made of cast brass or cast aluminum bronze, and hardness and strength are greater than the stem.

2.4 valve stem bushing material, its hardness and strength shall be not more than the valve stem, and steeped in water conditions and valve stem, valve does not form an electrochemical corrosion.

2.5 sealed surface of material: ① valve category varies, sealed way and the material requirements varies; II General wedge type gate, copper ring of material, and fixed way, and grinding way are should description; ③ soft sealed gate, valve Board lining rubber material of physico-chemical and the health detection data; II butterfly valve should marked valve body Shang sealed surface material and the butterfly Board Shang sealed surface material; they of physico-chemical detection data, especially rubber of health requirements, and anti-aging performance, and wear performance; usually used d fine rubber and the ternary b c rubber,, is strictly prohibited mixed with regeneration rubber.

2.6 valve axis filler: ① due to tube network in the of valve, usually is opening and closing not frequently of, requirements filler in number years not activities, filler also not aging, long-term keep sealed effect; II valve axis filler also should in bear frequently opening and closing Shi, sealed effect of good sex; ③ given above requirements, valve axis filler seeks to lifelong not for or more than 10 years not replaced; II filler if needed replaced, valve design should consider can has hydraulic of status Xia replaced of measures.