Edwina Dorsey Valves April 14th, 2019 - 12:32:35
As a rule customarily, the sealing face for the low-pressure valve mostly applies the brass or brozen. The sealing faces of the high or middle-pressure valves are made of stainless steel. If the valve has high requirement for the temperature or pressure, cobalt base alloy is used as the main material of the sealing face. What's more, the polymeric material is widely used in the valve field. For example, PTEF material is applied into the seat of ball valves, different rubber materials for seal packing ring of the butterfly valve and septum of the diaphragm valve. All in all, the sealability of these materials is better than that of metal in the available temperature range.
Another way of cheating customers - to use for the manufacture of shells cheaper metal - zinc. This is also the risk of counterfeiting. valve of zinc has increased brittle and may crack on the mechanical and hydraulic influences. There are ball valves, made from silumin (aluminum alloy). Their reliability is still lower. Savings metal induces dishonest manufacturers to produce the body taps with wall thickness from 1 to 0,5 mm. This is extremely reduces their reliability. (For comparison, the standard valves manufacturers Matca-Norca have a wall thickness of 2 mm).
A valve such as this operates the same as a ball valve. This valve contains a flat round plate that is placed in the middle of the pipe, as well as the plate has a bar inside that is joined to a switch in the outer valve portion. This type of valve functions by revolving the handle as well as the plate in similar position or vertical to the movement. Unlike the ball valve type, the butterfly valve is constantly present in the movement; thus there is always a moderate drop in the pressure in the movement regardless of the valve's position.
A few more examples from Swagelok's incredibly large catalogue of Valves for every need include Bellows-seated Valves, made with 316L Stainless Steel constructions, with Swagelok tube fitting, weld, and VCR ® and VCO fitting ® ends. Other features include full pressure rating in either flow direction for system versatility, and that the Valves are easily purged to maintain clean operation. Another type of Valve manufactured by Swagelok is the Check Valve which allows fluid to flow in one direction only.
All in all, step by step the valve manufacturing becomes one of the important sectors in the mechanical industry. There are a lot of applications for the valve. It is closely connected with our daily life. For example, the tap used for running water pipe and the reducing valve used for liquefied petroleum gas stove are the valves. What's more, it is the essential part for different mechanical equipments such as gas engine, steam engine, compressor, pump, vehicle, ship or aerocraft.
My goal is either a fake - under cover, used well-known brand, at minimal cost to create an external object like a fake. First, what saves the underground businessmen, it is - raw. Shells taps and ball valves shall be manufactured from special grades of brass, the chemical composition of which in USA are regulated by GOST and abroad - national standards. These standards include the copper content 57-60%, zinc - up to 40%, lead within 0,8-2,2%. (Lead is required to make the brass surface hardness). Illegal vendors typically use non-ferrous metals, the content of impurities which are not controlled. As a result, manufactured valves, the percentage of lead content in which, studies show that reaches 5-7%. It is well known that an excess of lead in water is very harmful to health.