Stainless steel needle 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 valve 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 valves .
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 .

The advantages and disadvantages of the fixed ball valve:

Advantage
1, double block and emission features: the fixed ball Stainless steel needle valve seat by spring preload variable, whether the valve is fully open or fully closed state, on the downstream side of the seat so that the fluid is blocked, the body cavity retentate through the discharge valve discharge.
2, automatic pressure relief feature: the valve body cavity retention medium caused by temperature rise when an abnormal pressure, without going through the safety Instrumentation ball valves, and the valve seat can only function of pressure relief automatically, which ensure that the safety valve in the delivery of liquid medium is very important.
3, fire safety structure: fire safety valve functions are available, the design, manufacture were to follow API 607 and API 6FA specifications.
Disadvantages
1, sealing grease emergency ambulance: as the foreign media or the fire caused the valve seat sealing failure, valve grease and grease gun provides a fast connection, import pump conveniently and quickly injected into the valve seat seal grease sealing parts, ease leak.
2, reliable stem sealing and low operating torque: in addition to setting the standard sealing ring, the packing gland has also set up O type sealing ring, double seals to ensure the reliability of the valve stem seals; addition of graphite filler and seal fat into the fire so that the valve stem leakage to a minimum. Stem bearings and thrust bearings so that the valve is easy to operate.
3, full size or reduced diameter: according to the selection of full size or necking structure needs. Full bore valve flow aperture consistent with the pipeline diameter, for pipeline cleaning.
4, the stem can be extended: according to the requirement of the installation or operation, the valve stem can be lengthened. Extension rod ball, especially suitable for urban gas pipeline laying occasions need buried. Long stem size according to customer needs to be determined.
5, the operation is flexible: the use of a small friction coefficient and good self lubrication of the valve seat and stem bearing, greatly reducing the valve operating torque. Therefore, even if not provided in the case of grease, but also the long-term flexibly operate on valve.

Male female connection line

Male female connection line is very simple, is a connecting line of a male connector and a female head Male connector component, known as the male female connection line. Male female connection line we common is DC line, public bus terminal, used for LED lamp and the driving power supply connection. DC public bus is injection molding, DC is the head of the welding is good, then the injection can be processed, public bus terminal, the terminal is cold pressed online material, and then inserted in the male and female connector inside, has become a public bus terminal. The public bus is convenient repair and maintenance, such as lighting a bad driver, a driver can directly, no need of welding.

Valve

The Check valve is in fluid system, a device used to control the direction of the fluid flow, pressure, is to make the piping and equipment within the media (liquid, gas, powder) device for controlling the flow of energy flow or stop and the.
The Instrument valves is a pipeline control unit of fluid delivery system, which is used to change the channel section and flow direction of medium, with diversion, cut-off, throttling, check, diversion or overflow relief functions. For fluid control valves, valve from the simple to the extremely different kinds of valve control system used in complex, its many varieties and specifications, the valve nominal diameter pipeline industry from large to tiny instrument valve diameter up to 10m valve. Can be used for the control of water, steam, oil, gas, mud, all kinds of corrosive medium, the liquid metal and radioactive fluids and other types of fluid flow, the valve working pressure is from 0.0013MPa to 1000MPa of ultra high pressure, working temperature from ultra low temperature to high temperature of 1430 DEG C -270 C.
The control valve can use a variety of transmission, such as manual, electric, hydraulic, pneumatic, pneumatic turbine, electromagnetic, electromagnetic hydraulic, electric hydraulic, pneumatic and hydraulic, gear, bevel gear drive; in pressure, temperature or other forms of sensor signals under the action, according to the requirements, or not depends on the sensing signal and a simple open or closed, the valve to rely on drive or automatic mechanism to make the opening and closing parts for lifting, sliding, rotating or turning motion, so as to change the size of the flow area to achieve the control function.

Ball valve features

One; wear resistance; because the valve core and hard seal ball Needle valve is alloy steel spray welding,
Three piece ball valve
The sealing ring is alloy steel welding, so the hard seal ball Instrument valve does not produce wear too much in the switch. (coefficient of hardness of 65-70):
Two; the sealing property is good; because the sealing hard seal ball valve is the use of artificial grinding, until the spool and the sealing ring is completely consistent to use. So his sealing performance is reliable.
Three; the switch light; because the sealing ring at the bottom of the spring and hard seal ball valve of the sealing ring and the valve core clung together, so in the pre tightening force of outside forces over the spring switch is very light.
Four; the service life is long, has been widely used in petroleum, chemical, power generation, paper, nuclear energy, aviation, rockets and other departments, as well as people's daily life.
Pneumatic ball valve has the advantages of compact structure, reliable sealing, simple structure, easy maintenance, sealing surface and spherical often in the closed state, the media can not easily be eroded, easy operation and maintenance for water, solvents, acids, and natural gas general working media, mainly used for cut off or connected tube road of medium, can also be used for the regulation and control of fluid.