3.Speed ​​gearbox

① Cabinet Material and external corrosion requirements and body principles.

② Measures should be sealed cabinet, cabinet assembly can withstand 3 m water column state of immersion.

③ Box on the hoist limit device, the adjustment nut should be in the cabinets.

④ Transmission structure design is reasonable, open and close valves can only drive shaft rotation so as not to traverse up and down, bite moderate transmission parts, no-load open and close when the separation skid.

⑤ Gear transmission box and the valve shaft seal leak can not be connected into a whole.

⑥ Cabinets no debris, grease should protect the gear meshing.

4.The valve operating mechanism

① The direction of the valve opening and closing operations, shall be clockwise closing.

② As the pipe network in the valve, often manually opening and closing, opening and closing rotation should not be too much, that is, large diameter valves should be transferred within the 200-600.

③ In order to facilitate a person's opening and closing operation, plumbing pressure conditions, the maximum torque should hoist 240m-m.

④Valve opening and closing operation should end mortise and tenon, and the size standard, and facing the ground so that people can be directly operated from the ground. With a wheel valve does not apply to underground pipe network.

⑤  Degree of valve opening and closing the display panel :

A. Degree of valve opening and closing lines of the scale should be cast in the gearbox cover or change the direction of the display after the disc casing, all for the ground wire brush on the phosphor scale to show striking.

B. Indicating needle plate material in the case of better management of available stainless steel, or steel for the painting, do not use aluminum leather production.

C. Direct needle plate striking, stable fixation, accurate adjustment when opening and closing, it should rivet locked.

⑥ If the valve is buried deeper, the operating mechanism and display the distance from the ground plate ≥ 1  5m should include extensions facilities, and fixed rate stability for the people from the ground observation and operation. That is, the pipe network in the valve opening and closing operation, should go down operations.

5.Valve performance testing

① Valve pressure in the working conditions of the opening and closing torque.

② Pressure in the working conditions, to ensure that the valve is closed tight continuous opening and closing times.

 valve in the pipe flow resistance coefficient under conditions of testing.

6.Valve at the factory should perform the following tests:

①Valve in the open position, the valve shall withstand value of two times the working pressure valve pressure testing;

②Valve in the closed position, the sides were exposed to 1  1 times the working pressure valve value, no leakage; but the metal sealed butterfly valve, leakage is no greater than the relevant requirements.

7.Valves and external corrosion

① Body (including the variable speed transmission box) inside and outside, first blasting sand blasting, non-toxic epoxy powder electrostatic spraying sought, the thickness of 0  3mm or more. Oversize valves electrostatic spraying toxic epoxy resin having difficulty, we should brush, spray non-toxic epoxy paint similar.

② Internal body and the valve plate all parts calls for a comprehensive anti-corrosion, while immersed in water will not rust, does not arise between the two metal electrochemical corrosion; two aspects of smooth surface to reduce drag through the water.

③ Valve body paint corrosion epoxy or health requirements, should the appropriate authority organs of test reports. Physical Chemistry Should be able to comply with the relevant requirements.

8.Valve packing and shipping

① Valve should be located on both sides of light blocking plate solid seal .

② Medium and small diameter valves should be tied to rope, and transported to suitable container.

③ Large diameter valves are also wooden frame retention packaging to avoid collision damage during transport.

9.The factory manual valve

① Valves are devices in the factory the following instructions shall indicate the relevant data.

② Valve specifications; model; work pressure; manufacturing standards; body material; Stem material; sealing material; valve shaft packing material; stem sleeve material; internal and external corrosion-resistant materials; operation starts direction; revolutions; work pressure conditions hoist torque; manufacturing plant name; manufacture date; serial number; weight; connecting flange diameter, number of holes, center hole distance; as icons indicate the overall length, width and height of the control dimension; valve flow resistance coefficient; effective opening and closing times; valve factory testing and installation of the relevant data, maintenance precautions.

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