Safety valve: it is through the valve automatically open the exhaust gas to reduce the high pressure inside the container.
1. Advantages: only discharge pressure vessel than is required as part of the pressure, and when the container pressure dropped to normal operating pressure, it is automatically closed so as to avoid once vessel overpressure must put all the gas discharge and cause of waste and production interruption. The device itself can be reused many times, and it is easy to install and adjust.
2. Disadvantages: poor sealing performance, even if it is in conformity with the provisions of the safety valve, under normal working pressure also inevitably have a slight leak; due to the inertia effect of the spring, the valve opening there is a lag and relief pressure response is slow. In addition, if the safety valve for medium for some clean gas, a valve is blocked and the valve is stuck may.
3. Scope of application: applicable in the medium is relatively clean gas and equipment such as air, water vapor, should not be used for devices has medium toxicity; not for is likely to have a violent chemical reaction to a steep increase in pressure equipment.
4. Selection of safety valve when its emissions must be greater than the safety of equipment leakage. And according to the process conditions of the equipment and working medium characteristics of the structure of the safety valve selection, according to the maximum allowable working pressure to choose the appropriate safety valve.
Note: the pressure vessel's safety relief volume refers to the pressure vessel in the overpressure to ensure that its pressure is no longer increased, in the unit time must discharge the gas volume. Safety valve displacement is the safety valve in the fully open state when the discharge pressure in the unit time of discharge.
Blasting piece: is the use of blasting components at higher pressure, the occurrence of fracture and emissions of gases (including: bursting disc for medium and low pressure vessels, bursting cap used for ultra high pressure vessels).
1. Advantages: good sealing performance, in the normal work of the container will not leak; bursting disc rupture velocity is high, and consequently the release of pressure rapid reaction; medium if they contain oil and other debris nor the device operating pressure influence.
2. Disadvantages: after completion of pressure relief action, blasting device is unable to continue to use, the container if over pressure to was forced to stop running; blasting element for a long time in high stress state, due to fatigue and premature failure, and component life is short, regular replacement. In addition, the actuating pressure of the bursting element is not easy to predict and strictly control.
3. The applicable range: suitable for chemical reaction is possible pressure increased sharply, or medium with toxic container, not easy for liquefied gas tank. For pressure fluctuations, that is, more than a chance to have more pressure vessels are not easy to use.
