Industrial valves are one of the most popular equipment in factories in Vietnam as well as in the world.
Because of the very simple reason the plant must use a waterway system (water is a very important substance no plant does not use)
The function of the valve is to regulate the flow of the fluid that flows to the will of the human (opening the flow of the medium, closing the flow of the fluid, flowing, small, flowing from the large pipe to the small pipe, flowing from the small pipe into the pipe)
Depending on the plant in which the valve is used or not, as well as depending on the line system that uses automatic valve or manual valve.
A number of factories use a variety of valves, such as: thermal power plants, nitrogen gas plants, chemical plants, beverage factories, food factories, feed mills. ... etc
Because of different characteristics of the industry, depending on the field, we have to choose different valves. But basically you can not ignore the following when buying a valve to replace a damaged valve:
1) It is important to know the liquid that the piping system is working on. (If the fluid is water, we choose the valve with plate is stainless steel, Seat washers are EPDM (synthetic rubber material). As a mild chemical, less corrosion, we can use NBR or EPDM Inorganic and Highly corrosive chemicals. Valves made of PTFE, or stainless steel, are covered with Teflon on the surface of contact with the media.
2) It is necessary to know the pressure and temperature of the pipe and valve system working with Seat EPDM seals. NBR is subject to a pressure of 10 bar and a temperature of less than 100 ° C. At high temperatures, the valve will be damaged. Then you have to choose more advanced material that is the disk control valve inox, the seat is padded with stainless steel 304 or Inox316. If the system has high pressure, the PTFE material must be selected. TEFLON materials can withstand up to 20bar pressure in the range of -50 oC to 300 oC.
3) The size of the valve is how many sizes are marked in Inch from 3/8 '' - 40 "'equivalent size 10A-1000A. What is the installation standard. Common valve and pipeline systems in the world have the following common standards: The JIS standard is the Japanese standard (JIS10K, JIS 20K, JIS 30K), ANSI standard is the American standard (ANSI 150 #, ANSI 300 #, ANSI 600 #). PN standard is European standard or used as PN10, PN16, PN20. If the valve on the pipe you are using is the JIS standard you purchased the ANSI standard valve for fitting there would be no joints, similar to valves using ANSI standard you purchased the standard PN valve fitting does not have, or Your valve is using JIS standard that you bought to PN standard back to lose money only.
Please note that it is important to choose the size of the valve and the duct.
The size of the valve is always smaller than the size of the pipeline. When we choose the wrong size leads to not be able to install valves and piping together.
I have listed the size of the valve and the size of the pipe for you to know
size valve 10A (mm) with pipe size 17 mm
size valve 15A (mm) with pipe size 21 mm
size valve 20A (mm) with pipe size 27mm
size valve 25A (mm) with pipe size 34 mm
size valve 32A (mm) fitted with pipe size 42 mm
size valve 40A (mm) with 49 mm pipe size
size of valve 50A (mm) with pipe size 60 mm
size valve 65A (mm) with 76 mm pipe size
size valve 80A (mm) fitted with pipe size 90 mm
size valve 100A (mm) with pipe size 114 mm
Size of valve is 125A (mm) with pipe size 140 mm
size 150A (mm) with pipe size 168 mm
size of valve 200A (mm) with pipe size 220 mm
Size 250A (mm) with 273 mm pipe
size 300A (mm) with 323mm pipe
Size 350A (mm) with 355mm pipe
Size 400A (mm) with 406 mm pipe
size van 450A (mm) with 457 mm pipe
Size 500A (mm) with 508 mm pipe
Size 600A (mm) with 609 mm pipe
size valve 700A (mm) with pipe size 711 mm
size 800A (mm) with pipe size 812 mm
size 900A (mm) with pipe size 913 mm
Size 1000A (mm) with pipe size 1014 mm
4) The valve system in the old pipe is the control valve, you need to know what is the control valve?
There are two types of control valves that are widely used in the factory. Pneumatic control valve and electric control valve.
There are two types of pneumatic control valves: double acting pneumatic control valve and single acting pneumatic control valve.
So when buying pneumatic control valves you and you need to look at the valve that you are using is a single-acting or double acting valve. The two types of valves have the common characteristics are the use of compressed air pressure control valves open. But dual-action pneumatic valves require air supply in both open and closed valves. The single-acting pneumatic control valve only provides compressed air for a state of the valve opening (for normally open valves). The valve is closed (for normally closed valves) because the second state does not require gas supply. Springs in the valve will make the valve thrust to the original position.
For electric automatic control valve, we need to know the valve that we are using is how much voltage 220VAC, 110VAC, 380VAC, 24VDC. Or automatic control valve with 4-20mA current, voltage 0-10VDC. The type of valve controlled by 4-20mA current, the voltage is 0-10VDC is the linear control valve. The opening angle is adjusted according to the needs of its use. It adjusts the opening angle from 0-100% as desired by the current level and voltage level.