Pneumatic - valve have spirit, gas close work on the two types of gas valve open along with the increase of signal pressure increases and the opening, pressure signal when the valve is in the fully open position, gas, on the other hand.
Reasonable choose the way to the role of regulating valve, to ensure production safety, improve product quality and reduce the economic loss is crucial.
Can also be based on the correct selection of gas, gas close way, reach the role of fault the position.
The regulator works should be selected according to the production process requirement to decide, consider when the signal pressure interrupts (
Such as regulating valve failure, instrument power outage or air supply interruption)
, depending on the control valve is open or closed position.
The harmfulness caused by the size of productive technology.
If less harmful when valve is in open position, choose the gas in the type;
On the contrary, choose open gas, usually consider the following factors: 1)
People and equipment safety first consider when there is a gas source supply disruptions, instrument power outage, each link in the control system has a fault and actuator diaphragm rupture, etc. , make the valve cannot work normally, as to make the valve core are in a state of no energy, regulating valve is open or closed position, should be able to guarantee the safety of person and equipment, not an accident.
Second consider the characteristics of medium adjust enters the medium flow process equipment, if medium is flammable, explosive or toxic gas, should choose to open gas, interrupted when the signal pressure, the valve is in close state, avoid harmful gas leak;
If medium is easy crystallization and easy to solidification material, to prevent clogging, elected for the gas type.
Finally consider the quality and reduce the economic loss when pressure regulating valve signal interruption and cannot work normally, the valve is open or closed, the product quality should not decline the waste and waste of raw materials and semi-finished products.