FRP Manhole Cover is made of composite materials;
we make the manhole cover on BS EN124, Mainly our products are A15, B125, C250
and D400. For A15, B125, C250 and D400 FRP manhole covers to be used in Green
belt, Pavement, Auxiliary road, Main road and Express way. We FRP manhole
covers all by press, the quality is very good, and we warmly welcome customers
all over the world to do business with us.
FRP Manhole Cover,FRP Manhole Cover Opening 550 B125,FRP Manhole Cover Opening 555 B125,FRP Manhole Cover Co 260 Zhoushan Runchun Import & Export Co., Ltd. , https://www.en124casting.com
Application of metal bellows in the valve
Metal bellows have the characteristics of pressure, axial force, lateral force or bending moment can produce the corresponding displacement, and with pressure, vacuum seal, corrosion resistance, temperature stability and long service life and other properties. Therefore, it is more and more widely used in many industrial fields. Bellows as a seal isolation element in the valve application. In a variety of bellows valves, whether it is cut-off valves, throttle valves, regulators or valves such as valves, bellows are sealed as a packing seal element. In the process of valve work, the bellows together with the stem axial displacement and reset. At the same time it also withstands fluid pressure and guarantees sealing. Compared with the packing seal valve, bellows valve with higher reliability and service life. Therefore, the bellows valve in the nuclear industry, petroleum, chemical, pharmaceutical and aerospace industries have been widely used. In practical applications, the bellows often with other components such as flanges, take over and stem welding such as one to form a bellows-like components. Welding has become an indispensable component in the production of bellows an important process. With the development of scientific research and production, new requirements are put forward on the corrugated pipe welding tools and equipment. According to these requirements, the need to develop a new bellows welding equipment.