principles for industrial valve selection-Belo Valve

Industrial valve is one kind of mechanical device which is necessary in various pipelines to connect, regulate, open and cut off the mediums like water, oils, gas,etc. 

Industrial valve includes butterfly valves( center line wafer butterfly valve, manual butterfly valve, lever driving butterfly valve, butterfly valve with worm gear box, lug type butterfly valve, soft seal butterfly valves, hard seal butterfly valves, flange butterfly valves, ductile cast iron butterfly valves, stainless steel butterfly valve,double eccentric butterfly valve, triple eccentric butterfly valve), gate valves(including DINF4 gate valves, DINF5 gate valves, DIN3352 gate valves, rising stem gate valves, non rising stem gate valves, soft seal gate valves, hard seal gate valves, hydraulic gate valves, sluice valves), globe valves( DIN globe valves, bellows globe valves, electric globe valve), ball valves( welded ball valves, soft seal ball valves, stainless steel ball valves, WCB ball valves, ductile cast iron ball valves, API ball valves), check valves( wafer type check valves, swing check valves, rubber disc check valves, ball type check valve, foot valve/bottom valve), fire protection valves( grooved butterfly valves, grooved gate valves, grooved strainers, grooved check valves), hydraulic control valves,etc.today we are going to talk about how to select a industrial valve in specific working conditions: 

1. selection principles of industrial valves for water supply pipeline: 

1.1. when the diameter of the pipeline is less than 50mm, a globe valve(or also called stop valve) should be selected; when the diameter of pipeline is larger than 50mm, a gate valve or a butterfly valve should selected; 

1.2. when the flow rate and water pressure need to be adjusted, the regulating valve and globe valve should be used; 

1.3. for parts with low resistance to water flow(such as the suction pipe of a water pump), a gate valve should be used; 

1.4. on pipe sections requiring bidirectional water flow, gate valve and butterfly valves should be used, and globe valves should not be used; 

1.5. where the installation space is small, butterfly valves and ball valves should be used; 

1.6. globe valve(or shut-off valves) should be used on pipe sections that are frequently opened and closed; 

1.7. a multifunction valve should be used on larger diameter pump outlet pipes; 

2. Where the industrial valve should be installed on water supply pipelines: 

2.1. industrial valve should be installed on the water supply line in the residential area coming from the incoming pipe section of the municipal water supply line; 

2.2. the nodes of the outdoor ring pipe network in residential area should be set according to the isolation requirements, when the annular pipe section is too long, a sectional valve should be installed; 

2.3. industrial valve should be installed on a branch pipe that connects to the main water supply in the residential area, or on a domestic pipes; 

2.4. industrial valves should be installed on household pipes, water meters and branch risers( bottom of risers, upper and lower ends of risers for vertical annular pipe networks); 

2.5. industrial valves should be installed on branch pipes of the annular pipe network and connecting pipes through the branch pipe network; 

2.6. industrial valve should be installed on the end of the water supply pipe which connects the indoor water supply pipe to the household,public toilets,etc; when there are more than 3 water supply pipes, set the water supply point on the water supply branch pipe; 

2.7. industrial valve should be installed on pump outlet pipe, suction pump of self filling pump; 

2.8. industrial valve should be installed on the inlet and outlet pipes of water tank, and drain pipes; 

2.9. industrial valves should be installed on the water inlet and make-up pipes for equipment( like heaters,cooling towers,etc); 

2.10. industrial valves should be installed on the water distribution pipes for sanitary equipment( like urinals, washbasins,shower,etc); 

2.11. industrial valves should be installed on some accessories before and after the pressure reducing valve ad back flow preventer, such as automatic exhaust valve, pressure relief valve, water hammer arrester, pressure gauge, sprinkler,etc; 

2.12. the drain valve should be located at the lowest point of the water supply network; 

3. how to select a check valve: 

Before we discuss how to select a check valve, we should know first how many types check valve has: generally, we have check valves like single door wafer butterfly type check valve, double door wafer butterfly type check valve, lifting type check valve, swing check valves, rubber disc check valve, ball type check valve, foot valve(or bottom valve),etc, with body material WCB, ductile cast iron, stainless steel, forge steel, etc; 

The check valve should generally be selected according to the following factors: installation location, water pressure before the check valve, airtight performance requirements after closing, and the size of water hammer caused by closing: 

3.1. if the water pressure in front of the valve is small, the swing check valve, ball valve and shuttle valve should be used; 

3.2. when the airtight performance after closing is strictly required, a check valve with a closing spring should be selected; 

3.3. when the cut-off water hammer needs to be weakened, a quick-closing silencing check valve with a damping device or a slow-closing check valve should be selected; 

3.4. the disc and trim of check valve should be able to close automatically under the action of gravity or spring force; 

4. where the check valve should be installed on water supply pipelines: 

4.1. check valve should be installed on inlet pipes; 

4.2. check valve should be installed on the inlet pipe of a closed water heater or water appliance; 

4.3. check valve should be installed on the outlet pipe of the water pump; 

4.4. check valve should be installed on the outlet pipe section of the water tank, water tower and the upland pool, the inlet and outlet pipes are combined; 

Notes: it is not necessary to install a check valve on the pipe section equipped with the pipe back flow preventer; 

5. where the air exhaust device should be installed in water supply pipe: 

5.1. for intermittent use of the water supply network, the end and highest point of the network should be equipped with automatic exhaust valves; 

5.2. the water supply pipe network has obvious undulating pipe sections, which accumulate air. At the highest point of this section, an automatic exhaust valve or a manual valve is set for exhausting; 

5.3. Air pressure water supply device. When using an automatic air supply air pressure water tank, the highest point of the water distribution network should be equipped with an automatic exhaust valve;