Conditions Instrument needle valve inspection

Instrument needle valve is a simulation test in the normal state. This state should be able to cover all water department environment. Dynamic test valve executive function Another very important point is that the test voltage, what kind of voltage the most appropriate? High pressure ball valve Smart meter in every one has a same function, that is, when the battery voltage is below the set value, the microcontroller will command the valve closing function is activated,Valve manifolds when the battery voltage is the lowest in the smart meter voltage Instrument needle valve, also that is, the final action is the lowest setting off valve in the battery voltage. The task of the truth is by reversing valve to the valve dredge or occlusion. Instrument needle valve switch is lightweight, small size, can be made very large caliber, reliable sealing, simple structure, Instrument needle valves convenient maintenance, regular spherical surface and seal in the closed condition, can not easily be eroded media, in all sectors lost universal use.

Needle valve selection principles

1 , the pipeline system and cryogenic medium , should use plus low bonnet needle valve .
2 , the pipeline system FCCU refinery unit , optional Needle valves lift rod .
3 , fixtures and piping systems , such as acid-base chemical systems in corrosive media , should use austenitic stainless steel , Teflon seat ring in stainless steel needle valve .
4 , metallurgical systems, piping systems or devices on the power system , petrochemical plants , urban heating systems in high-temperature medium , the choice of metal to metal seal needle valve .
5, the need for flow regulation , the choice of the worm gear , pneumatic or electric adjustment with a V -shaped opening needle valve . 6 , transmission mains oil, natural gas , it is necessary to clean the pipeline , buried in the ground and the need , use full bore , all-welded construction needle valve ; buried in the ground , choose full bore welded or flanged connections the ball valve.
7 , pipelines and storage facilities for refined oil products , the choice of needle valve flange connection .
8 , city gas and natural gas pipeline , the choice of the Needle valve flange and the threaded connection .
9 , metallurgical oxygen pipeline system , should use rigorous degreasing treatment , needle valve flange connection .

Instrumentation needle valve Product Description

Instrument measuring Instrument needle valve  is an important part of the piping system, the main shut-off valve and ball valve, its function is to be used to turn on or off the pipeline path. Card sets with easy installation and removal instrument valves, connections are tight, there is conducive to fire, explosion and high voltage capability, good sealing performance, etc., are power plants, oil refineries, chemical plant piping and instrumentation to measure an advanced connection valve. Needle shut-off valve sealing good, long life, even after the sealing surface is damaged, only need to replace wearing parts, you can continue to use.

Instrumentation needle valve

Instrument needle valves, instrument measuring the piping system is an important part of the main shut-off valve and ball valve, mainly used for cutting the pipe open or access available. Installation Notes: Valve must be visually inspected prior to installation, the valve plate should comply with existing national standards, "Universal Valve logo" GB 12220's. The outer surface of the instrument needle valve body also affected by atmospheric corrosion, general steel materials to paint to protect.

The classification of ball valve

One, floating ball valve
Ball High pressure needle valve ball is floating in the medium under pressure, can produce some displacement of the sphere, and pressed in the export side of the sealing surface, to ensure that the exit seal. Floating ball valve structure is simple, good sealing, but the ball under the load of all media work to export ring, so to consider the ring material can withstand the work load of the media sphere. This structure, widely used in low-pressure Stainless steel needle valve
Two, fixed ball valve
The ball valve is fixed, no movement after compression. Fixed with a floating ball valve ball valve seat, by the media pressure, the valve seat have a mobile, so that the sealing ring is pressed on the sphere, in order to ensure the sealing. Usually with the ball in the upper and lower shaft with bearings, operating torque, suitable for high pressure and large diameter of the valve. In order to reduce the valve operating torque and increase the reliability of the seal, valve seal has emerged in recent years, both pressure lubricating oil special note in the sealing surface, to form a layer of oil film, which enhances the sealing, and reduce operating torque, more suitable for large-diameter high-pressure valve.
Three, elastic ball valve
The ball valve is flexible. Ball and valve seat rings are made of metal materials, sealing pressure than the large, rely on the media itself can not seal the pressure has reached the requirements must be imposed by external forces. This valve is suitable for high temperature and high pressure medium. Elastic sphere is a flexible open slot in the sphere of the bottom wall, and get flexible. When the closed channel, with the stem of the wedge-shaped head to open up the ball with the valve seat to seal compression. In the rotating sphere before loose wedge head, ball the subsequent restoration of the original prototype, so that a small gap between the ball and the valve seat sealing surface can reduce friction and operating torque.

Trunnion ball valve using the principles of

Trunnion ball valve is guaranteed by the pressure poorly. Flat stack valve to valve flatness and smoothness requirements friction plane quite high, and the requirements for the use of materials Instrument needle valve also have high demands. To solve these problems, flat lamination stack valve using a ceramic substrate under the topsheet other using a high-strength wear-resistant material, in full accordance with the principles of chemical mechanical seal manufacturing and processing, both to ensure a reasonable contact surface, and ensure the minimum coefficient of friction. Trunnion ball valve has emerged cause Valve manifolds quality problems due to prolonged blockage of the pilot hole, the pressure relief valve stem causing the valve stem is stuck adsorption of iron particles and other issues, through the use of market information and feedback, developers have learned Trunnion ball valve actuators Division is currently unsuitable water quality of water use. Thus, the developers turned to the ball and flat stack valves. Now use the ball a little more.