With proportion of plastic pipes in hot and cold water supply and industrial pipeline engineering application has improved a lot, the actuators lifespan and quality control is more and more especially important.
There are many advantages of the electric actuators, including light, corrosion resistance, no adsorption scale, long life and so on. In addition, the electric actuators also can be connected to the integration of plastic pipe. Actuators are used in water supply (especially hot water and heating) and other fluid plastic piping system, its application advantages are obvious compared to other valves. At present in domestic production and application of actuators, there is no reliable way to control it, causing the quality and lifespan of water supplies and other fluid actuators used in industry product is uneven. In the engineering application the closed lax and leakage phenomenon is serious, forming the formation that actuator cannot be used, which affects the overall development of plastic pipe application.
The national standard of electric actuators
in our country is in developing process, the actuators lifespan and product standard are formulated according to the international standard.
International valves types mainly include ball valve, butterfly valve, check valve, diaphragm valve and globe valve and so on, there are mainly two structure forms, tee and multiport valves, its raw materials are mainly include ABS, PVC -u, PVC - C, PB, PE, PP and PVDF, etc. In international standards of plastic products, the first is the requirements of valve production, its raw materials manufacturers must have plastic pipe product standard. They set all the rules for actuator sealing test, body long-term performance test, the whole valve test, fatigue test and operating torque and so on, actuators used for industrial to convey fluid is given the requirement of the actuators lifespan of 25 years.
Main technical requirements of the international standard
1.1 Raw material requirements
Body, bonnet and valve cover materials should be chosen in accordance with ISO 15493:2003 "industrial electric actuators.
1.2 The design requirements
A) If the actuator has only one pressure direction, we should mark it outside the external body with the arrow mark, symmetrical design of valves shall be suitable for two-way flow and isolation, which is good for actuators lifespan.
B) The sealing parts carry on opening and closing action by stem drive valve. We should perform positioning in the end, or any intermediate position by friction or device to make the fluid pressure will not change its position.
C) According to EN736-3, the valve lumen minimum hole should meet the following two points:1. For any size valves medium circulation, it should be no less than 90% of the valve DN value.
D) The seal between the valve stem and valve body should be accordance with the EN736-3, which is a essential requirement for actuators lifespan.
E) In terms of wear resistance of valve, the valve design should consider the service life of wear parts, or producer should be indicated in the operating instructions of replacing the entire valve are suggested.
F) The applicable velocity of all valves operation device should reach 3 m/s.
G) From the top of the valve, the valve handle or handwheel should close the valve clockwise.
Featured Products: electric rotary actuator | rotork pneumatic actuator