Adjustable safety valves are of great importance for the safe operation of any systems in which water, steam or another substance can be exposed to strong pressure. The pipeline through which it passes cannot keep the pressure. As a result, an explosion can occur with all the ensuing consequences. What are the adjustable safety valves, how do they work?
Safety Valve Functions
Adjustable safety valves relate to direct-acting shut-off valves. They work directly with the environment that implements production processes. Most often it is water. Instead, it can be air, steam, natural gas, ethylene glycol or other substances that do not interact with the materials used to make the valve.
The pressure- controlled safety valve has two functions. First, it releases the working medium with increasing pressure inside the system. But then he also blocks the exit from it. This happens immediately after the pressure inside the system has stabilized.
Application
Adjustable safety valves are installed on:
- industrial systems;
- household.
They prevent the influence of external and internal factors. The first include various malfunctions in the operation of the equipment or the influence of external sources of elevated temperature. These may be errors during installation of the system or device.
Internal factors are physical processes within a device or system that result in increased pressure.
Principle of operation
The operation of the valve is based on the fact that inside it there are two elements that are in equilibrium for some time. A part called constipation keeps the mixture from exiting the system. It is not allowed to move the setter (spring), which has a certain compression force. But when the pressure inside the system passes the line defined by the operator, the spring is no longer able to hold the lock. It is compressed, the constipation (sleeve) rises, and the medium under pressure comes out - where the valve design will direct it.
After the pressure stabilizes, the spring returns to its original position, pushing the lock into place.
Valve requirements
They have to:
- In time and without fail to open a lock with the specified pressure parameters.
- With a capacity to quickly reduce overpressure.
- Be sure to return the constipation in place, ensuring the tightness of the system.
Classification
It is carried out according to various parameters.
According to the principle of operation, safety valves are direct and indirect action (in order for it to work, you need a source of electricity).
They can be separated according to the material from which they are made (brass, cast iron, steel).
By the nature of the constipation rise, the valves are divided into proportional and on-off devices.
In addition, the valves can be small-, medium- and full-lift. And this is not all possible classifications.
The safety valve regulated Geneble 3190 (Spain)
According to the type of connection, it refers to the coupling. The working medium may be water, steam, neutral gases and liquids.
Its body is made of high quality bronze. The 1 '' adjustable safety valve has a brass body. Spool and glass brass. The spring is made of galvanized steel. Teflon gasket.
The operating pressure of the valve is 16 kgf / m 2 (bar).
Pressure is regulated from 1 to 12 kgf / m 2 . At the factory, this value is set to 3 kgf / m 2 .
The response pressure is adjusted with the adjusting screw. If you turn it clockwise, the value increases, but if it is against, then it decreases accordingly.
Overpressure up to 10% of the norm is allowed.
Operating temperature from -10 ° C to 180 ° C, the maximum is 200 ° C.
Mounting
In order to correctly install the valve, you need to look at the direction indicator of the medium located on the body.
Placement of the valve must be vertical, otherwise it will not work.
In order that the working environment does not leak, use materials that do not react with it.
For installation, install the valve on the pipe and clamp it with a key to the mark inside the thread. The nut must not be pinched. The outlet pipe is directed downward so that the liquid does not come back, and fixed so that it does not press on the body.
Valtec Adjustable Valve
Valtec 1831 coupling adjustable pressure relief valve discharges water or another working fluid (gas) after the pressure in it rises above the permissible value.
Valve device
The spool with gasket is located inside the housing. It is supported by a spring located in a glass, which protects it from exposure from the outside.
The degree of compression is adjusted using a thrust washer. The forced opening sleeve, which is held on the stem with two nuts, comes into contact with the adjustment sleeve. Thus, the spring is compressed, but not critically.
When the pressure rises above normal, the spring contracts more tightly, the spool opens. Water or other substance exits through the nozzle. The pressure drops, as required by the valve.
After the pressure has dropped and returned to normal, the spring opens. After all, the sleeve on it no longer presses so much. The system is sealed.
Specifications
The diameter of the seat can be from 1/2 '' to 2 '' in increments of 1/4 '', 2, 2½ '' and 3 ''.
The full opening pressure is 1.1 of the setting pressure, closing is 0.9 of the setting pressure.
The working temperature of the medium is not higher than 180 ° C.
The valve operates in the temperature range from -25 ° C to 60 ° C (for water).
Moreover, it is designed for 5 thousand cycles and usually serves at least 15 years.
Warranty and insurance are valid for all Valtec valves up to 7 years.
Adjustable safety valves can be opened manually. This is done in order to check their serviceability. It is advisable to check them every six months.
Adjustable safety valves Geneble and Valtec comply with GOST 12.2.085-2002 and GOST 24570-81.