Check Valves

ZWICK TRI-CHECK SERIES

zwick check valve

The check valve TRI-CHECK combines all the benefits of the Series TRI-CON in a non-return valve. Triple-offset design with a wide seat angle and a true cone in cone, no rubbing while moving and absolute zero leakage performance.

Also the statically held gasket and the no pinned disc design are used in the Series TRI-CHECK. The TRI-CHECK is equipped with a hydraulic damper and a counter weight. The damper can be adjusted to the actual installation conditions in which the valve will be used.

ZERO LEAKAGE!

The hydraulic damping system not only reduces the risk of pressure surges due to waterhammer because of its closing characteristic, it also prevents the disc to slam in the seat. Instead the disc closes in a smooth movement which can be adjusted, so that the valve closes slowly in the last degrees of movement to protect the sealing parts. The Check Valve Series TRI-CHECK has proved to be the ideal non-return valve for single or multiple pump protection application for the last two decades.

Another benefit of the valve is the variety of features. Beside the non-return function the valve can be used as a combined check and isolating valve or as a check valve with power assisted closing and opening.

 

CUSTOMISED SOLUTIONS

The Series TRI-CHECK uses a seat design which is diagonal to the flange facing in the body. As a consequence the general flow path will be increased, so that the fluidic resistance of the valve will be decreased.

Another advantage is that the valve travel will be reduced, so that the valve reaches its ideal position in the flow much faster. Zwick also uses the latest EFD simulation technology to optimize the design of the series TRI-CHECK and to achieve the best possible hydrodynamical characteristics.

 
 

A check valve, non-return valve or one-way valve is a valve that normally allows fluid (liquid or gas) to flow through it in only one direction. A check valve is an electronic equivalent of a diode which permits the flow of electrical current in one direction only. The various practical applications of check valves are as follows.

Single pump systems

This is the most common application of a check valve where a check valve permits flow from suction tank to the discharge tank and prevents the reverse flow from the discharge tank back to the suction tank during pump stoppage or pump failure.

Parallel pump systems

This is another common application of check valves. In this configuration two or more pumps are connected in parallel. The check valve has two functions in such a scenario:

  • The check valve prevents the duty pump, pumping into the standby pumps
  • The check valve prevents the discharge tank back flowing into suction tank during pump stoppage.

Series pumping systems

When pumps are connected in series especially when pumping fluids in cross country pipelines then it is recommended to place check valves in parallel to each pump. Under normal operation the discharge pressure of the pump will keep the check valve in closed position. However if any pump fails then the pressure drop across the pump will activate the check valve. This will split the flow in two streams and reduce the hydraulic losses. 

Emergency cooling systems

This is a smart way of using check valves. Under normal operation only a small amount of fluid will go to the header tank and the same amount will overflow and drain back into the suction tank. So in effect the header tank will be always charged with water. The main flow will go through the load. 

Pressure relief systems

Spring loaded check valves are commonly used in gas projects as relief valves for low pressure applications.

Vacuum breaker systems

Check valves can also be used as vacuum breakers. 

Mixing streams

Check valves can also be used to maintain the purity of individual streams before they mix.

ECONTROL Check Valves

econtrol check valVe

The ECONTROL VR-100 Check Valves are a complete family of backflow preventer valves for a wide range of industrial applications.

 In every piping system, there is a need for backflow prevention. Most piping systems utilize pumps or compressors to generate needed pressure for movement of line fluids or gases. When rotating equipment stops, flow reversal or backflow occurs. Check valves (also non-return valves) are used to stop backflow and protect rotating equipment or other mechanical devices from the sudden backflow surges that may occur.

Our check valves are mechanical valves that permit gases and liquids to flow in only one direction, preventing process flow from reversing. They are classified as one-way directional valves. Fluid flow in the desired direction opens the valve, while backflow forces the valve closed. Our range of non-return valves is suitable for oil, gas, water, refining, power and chemical applications where the prevention of flow reversal is mandatory. Check valves can be supplied with a cast or forged body design for high pressure applications or fully lined to meet specific requirements within the chemical industry.

The VR-100 series are available in a number of design sub-families such as swing check valves, tilting check valves, forged steel lift check valves (flanged or flangeless), nozzle check valves…

Materials:

BodyASTM A216, A105, A350, A182, A351, A352, A890, A995, C95300, C95800, A494 CW6MC, MONEL, INCONEL. Please enquiry for different material configurations
TrimASTM A216, A105, A350, A182, A351, A352, A890, A995, C95300, C95800, A494 CW6MC, MONEL, INCONEL. Please enquiry for different material configurations
Seat(s)PTFE, NYLON, PEEK, NBR, KELF, ENP (Electroless nickel plating), HC (Hard chrome), TC (Tungsted carbide). Please enquiry for different material configurations
SealingBUNA-N, EPDM, VITON, Flexible graphite, FKM, HNBR, Nitrile, Neoprene. Please enquiry for different material configurations
Manufactured sizesNPS 1/4″ thru NPS 60″
Pressure ratingsANSI 150#, ANSI 300#, ANSI 600#. ANSI 900#, ANSI 1500#. Please enquiry for higher or lower ratings
Valve connectionsASME B16.5 (FF, RF, RTJ, Threaded), ASME B16.47 Series A or B, MSS SP-44, ASME B16.25 (BW, SW, WE). Please enquiry for special connections
StandardizationAPI 6D, API 594, API 6FA, BS 6755 Part 2, ASME B16.10, API 598, NACE 01-MR-0175, FCI 70-2. Please enquiry for other standards

A check valve, non-return valve or one-way valve is a valve that normally allows fluid (liquid or gas) to flow through it in only one direction. A check valve is an electronic equivalent of a diode which permits the flow of electrical current in one direction only. The various practical applications of check valves are as follows.

Single pump systems

This is the most common application of a check valve where a check valve permits flow from suction tank to the discharge tank and prevents the reverse flow from the discharge tank back to the suction tank during pump stoppage or pump failure.

Parallel pump systems

This is another common application of check valves. In this configuration two or more pumps are connected in parallel. The check valve has two functions in such a scenario:

  • The check valve prevents the duty pump, pumping into the standby pumps
  • The check valve prevents the discharge tank back flowing into suction tank during pump stoppage.

Series pumping systems

When pumps are connected in series especially when pumping fluids in cross country pipelines then it is recommended to place check valves in parallel to each pump. Under normal operation the discharge pressure of the pump will keep the check valve in closed position. However if any pump fails then the pressure drop across the pump will activate the check valve. This will split the flow in two streams and reduce the hydraulic losses. 

Emergency cooling systems

This is a smart way of using check valves. Under normal operation only a small amount of fluid will go to the header tank and the same amount will overflow and drain back into the suction tank. So in effect the header tank will be always charged with water. The main flow will go through the load. 

Pressure relief systems

Spring loaded check valves are commonly used in gas projects as relief valves for low pressure applications.

Vacuum breaker systems

Check valves can also be used as vacuum breakers. 

Mixing streams

Check valves can also be used to maintain the purity of individual streams before they mix.

Product Range

Econtrol swing check valve

8" ANSI 900# (API 6D) - Swing Check Valve during curing stage

econtrol nozzle check valve

20" ANSI 900# (API 6D) - Nozzle Check Valve

econtrol severe service check valve

8" ANSI 1500# (API 6D) - Severe Service Check Valve

econtrol nozzle check valve for severe service

Nozzle Check Valve For Severe Service

econtrol swing check valve1

8" ANSI 900# (API 6D) - Swing Check Valve

econtrol dual plate check valve

52" ANSI 150# & 32" ANSI 300# (API 6D) - Dual Plate Check Valve in NiAlBr