Butterfly valve

butterfly valve may include a pressure-tight resilient seat and an angularly offset disc. butterfly valve designs use a hard seat and an O-ring or piston ring around the disk to seal.

Butterfly valves range in size from small to enormous, and are well suited for large flows of gases, liquids, or slurries, offer a number of advantages when used for the proper application. They may be used in a wide variety of chemical services, they are available with small dimensions allowing for use in areas where space is limited, and they allow a high coefficient of flow.

Conversely, the design of butterfly valve creates the disadvantage of not being easy to clean, and therefore should be avoided in situations that call for sterile, medical or food processing applications.

Additionally, some styles may have difficulty dispensing slurries.

Plug Valve

Plug valves, also called cock or stop-cock valves, date back to ancient times, where they were developed for use in citywide Roman plumbing systems.
Today, they remain one of the most widely used valves for both on/off and throttling services.
Their design is fairly simple; the body is comprised of three main parts: body, cover and plug.
The plug is a cylindrical, tapered, or generally cone-shaped device that can be raised or lowered within the seat to maintain, restrict or completely shut off flow.
The valve is opened by rotation, with the plug itself being the only element that is capable of movement.
models of plug valves used metal-to-metal seals that were nonlubricated. This design is still used, but problems with galling and sticking limit their usefulness.
The use of lubricant between the plug face and the seat eliminates most of these problems. The lubricant helps to control leakage around the plug, reduces wear between the valve contact surfaces, and slightly lifts the plug to reduce the operating torque required to operate the valve.

Ball Valve

ball valves are the three different types of rotary valves used in industrial plants. They are widely used in fluid-handling systems for flow control.
These types of rotary valves are suitable for corrosive applications. They are used in detergent, pharmaceutical, chemical, rubber, pulp and paper plants, water treatment systems, textile mills and food processing plants, In general, ball valves offer many advantages when contrasted with other valve types.
They provide superior ease of operation and can maintain and regulate high volume, high pressure and high temperature flow.
Most ball valves offer rugged construction providing for a long service life, and a comparably low cost.
Additionally, the design of the regulating element allows the valve to function without the complications of side loads, typical of butterfly or globe valves, and the valve design permits inspection and repair of seats and seals without removing the valves’ body from the line.

CHAODA valve: Ball valve,Gate valve,Check valve,Globe valve,Butterfly valve,Plug Valve,Flanges

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Valve:Introduction of flameout protector

The purpose of flameout protector
When we use the cook top, the fire may be extinct because of the wind or overflowing water. In this case, the protector may cut off gas to prevent some accidents happening because of its leakage, such as poisoning, explosion or fire. In this way, it realizes its safety protection function.

• Working sketch-map of flameout protector

• The first step: Piezoelectricity
  
• The second step: Valve-open condition
  The top of the thermocouple is heated by fire, and it causes thermo electromotive force. Then it will be in series between the closed circuit and the valve. Outside force and the magnetic field breathe the valve and keep it open, and the gas channel is open.
  
• The third step: Cut off gas in sudden flameout condition
  When the fire is extinct because of wind or overflowing water, the thermo electromotive potential will minish quickly, and the ferrite core will come back to its original place to cut off the gas because of the loss of the spring effect.
  
• Attention:
  1. Thermocouple
  1) There mustn’t be any damage or peeling off for the cover of insulation wire or insulation sleeve, otherwise it will cause short circuit, which will influence the normal operation of the valve.
  2) The fix-up of the thermocouple must dissipate heat to reduce the heat accumulation of fixing board and thermocouple copper. This can shorten the valve-closing time when there is sudden flameout.
  3) The heated part of a thermocouple must be on the top of 2-3mm. Not to put the top into the fire, otherwise it may reduce the potential and shorten its life.
  
  2. Solenoid valve
  1) Prevent the valve from being strongly striken in the process of installation and shipment, otherwise it may influence its normal performance.
  2) Before installation, the user must check the valve flatly on the test clamps with some prepressing. It is not allowed to be freely-flip. This assures that magnetic material won’t be damaged by colliding, otherwise it will influence the magnetic force.
  3) Clean the impurity such as aluminum or oil left on the inner wall of the stove and the surface of the valve.
  4) Keep the good connection of the solenoid valve and thermocouple. Prevent the safety protection device from operating abnormally because of too big contact resistance.
  5) The warehouse of solenoid valves must be dry and ventilated and strictly prohibit extrusion.