What type of ball valve should be used for the ball valve on the nitrogen cylinder?
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Can a stainless steel flanged ball valve be used for the ball valve on the nitrogen cylinder? Are the fastening bolts for flanged ball valves made of stainless steel 304, and what is their strength grade? Also, are spring washers and flat washers needed for the flange bolts?
Nitrogen-inert gases – valves made of carbon steel will work, and those made of stainless steel are also suitable. Bolts and nuts are selected based on the operating pressure; for lower pressures, stainless steel is an excellent choice. Stainless steel bolts of types A2-50, A2-70, A4-50, and A4-70 are available, and details can be found in HG/T20613-2009. Flat washers and spring washers are generally not required. Selected appropriately based on user requirements and the range of pressure and temperature fluctuations, flat washers are generally used to compensate for oversized bolt holes, while spring washers are used for self-locking and compensating for preload.
I still have a question: the design pressure for the tank is 16 kilograms per square centimeter. But the nominal pressure of the flange on the flange interface is marked as 25 kilograms. If I need to install a ball valve now, should it be of 25 kg class or is 16 kg class sufficient?
The valve with a weight of 25KG is compatible with the flange.
Stainless steel is completely suitable; use it without hesitation
This post was last edited by bluishice on 2019-9-27 at 10:59. If the flange weighs 25 kilograms, then the valve must also weigh 25 kilograms; this is mainly to ensure that the flange of the valve can be fitted together with the flange of the equipment. Of course, if you find that the dimensions of 25-kilogram class flanges are the same as those of 16-kilogram class flanges, then using 16-kilogram class flanges is also an option. However, for aesthetic reasons, it is generally preferred to use flanges of the same class, even though the 16-kilogram and 25-kilogram class flanges may be identical in size