Home About Us Valve Selection / Sizing Products Contact Us Enquiry
Piston Valve

Piston valve was Innovated by replacing the disk and seat of a conventional globe valve with a cylindrical piston and two resilient, replaceable sealing rings.  Constant research and development have resulted in sealing rings that provide the piston valve with an extraordinary ability to seal line pressure and prevent leakage to the atmosphere. 
 Independent testing laboratories have subjected piston valves to API fire tests and Helium leak tests.  The piston valve has out-performed other generic valve types in these tests; and these results have been consistently confirmed by extraordinary performance in customer installations.

 

An extraordinary sealing system: Amazingly simple and reliably tight :
A stainless steel piston enclosed by two valve rings makes up the sealing element. The upper valve ring provides the stem seal, white the lower valve ring seals the passage. The large sealing surface on the piston and rings provides an optimal seal.
When closing the valve, the piston pushes and wipes away any impurities, which might be present in the fluid, ahead of itself. Therefore media with fibrous or contaminated constituents are reliably sealed.

Excellent control characteristics :
The double guidance of the piston in the closed position prevents fluttering and vibration in the throttled position and is better able to handle turbulence in the pipeline. The KVN is ideal for the bypass around a modulating control valve.

The valve stays in the line while changing the valve-rings :
Once installed, the valve is absolutely maintenance free for a long time.In case worn valve rings have to be changed, this is very easily done with the valve in the line.

FEATURES :

  • Larger effective sealing area :
  • Leak proof isolation - Class 6 shut off achieved.
  • Durability - Piston unexposed to media
  • Absence of Gland & Seat
  • Maintenance friendly - Uniform sealing rings on both the sides & maintenance can be done without removing the valve from the pipe line. (On-line Maintenance)
  • User Friendly - It does not need Valve Key
  • The Only Scrap Free Valve
  • Self Lubricating
  • Self Cleaning

RANGES:
FORGED CARBON STEEL (A105) WITH SS INTERNALS 15 NB, 20 NB, 25 NB, 40 NB,50NB in socket weld, Butt Weld ends as well as Screwed BSPT /NPT Ends For socket weld, Butt Welded ends, Max Operating Pressure : 78 kg/cm2 Max Operating Temperature : 427 deg. C CAST CARBON STEEL (ASTM A 216 WCB ) WITH SS INTERNALS 15NB to 200NB in ANSI Class-150 and Class-300 Max working Conditions: 40 kg/cm2 at 400 deg C VALVE STANDARD ANSI B 16.34 , API 598, IBR / N IBR

APPLICATIONS :

  1. EXCELLENT PERFORMANCE IN STEAM SERVICE
  2. PREFERD VALVE FOR THERMIC FLUID SERVICE(HIGH TEMP. 2500C AND UPWARDS)
  3. FATTY ACID
  4. GASSES AND HAZARDOUS FLUIDS.

Special Applications :

  1. JACKETED VALVES
  2. REGULATING VALVES
  3. ATUATED VALVES
  4. VALVES WITH LOCKING ARRANGEMENT
  5. EXTENDED SPINDLE
  6. VACUUM VALVES

LIMITATIONS
  1. SIZE –CANNOT BE MORE THAN 200MM AS TORQUE REQUIRED TO OPERATE THE VALVE WILL BE A LIMITING FACTOR.
  2. PRESSURE CLASS- ALTHOUGH IT IS VERY GOOD FOR HIGH TEMP.(UPTO 5400C) BUT WE CANNOT CROSS#300(IN FLANGED) AND #800 IN SOCKET WELD VERSIONS BECAUSE OF THE SOFT RINGS.

WHAT IS A PISTON VALVE:
PISTON VALVE IS A SEATLESS (SOFT SEATED) , GLANDLESS PISTON TYPE GLOBE VALVE


PRINCIPLE OF OPERATION
SEALING BETWEEN PORTS IS ACHIEVED BY PISTON (OUTER SURFACE) COMING IN CONTACT WITH THE INNER SURFACE OF SOFT RING (THE LOWER RING).
SEALING TOWARDS ATMOSPHERE IS ACHIEVED BY THE PISTON TRAVELING UPWARDS AND BY FORMING THE SEALING (OUTER SURFACE OF PISTON AND INNER SURFACE OF UPPER RING). HENCE NO GLAND IS REQUIRED.

ADVANTAGES OF PISTON VALVE OVER GLOBE VALVE :

  1. SOFT SEATED VALVES FALL UNDER CLASS VI
  2. DOES NOT GET AFFECTED BY FOREIGN MATTER.
  3. LARGE SEALING AREA BETWEEN OUTER SURFACE OF PISTON AND INNER SURFACE OF THE RING 950 MM2 FOR 25NB.
  4. UNIQUE DESIGN OF PISTON & LANTERN BUSH CAN PROVIDE GOOD REGULATION WITH LINEAR CHARACTERISTICS.
  5. BELLEVILLE (INVERTED CUP) WASHERS COMPENSATE FOR THERMAL EXPANSION NO THERMAL CHATTERING DUE TO SOFT SEATING
  6. EASY TO MAINTAIN BY REPLACING RINGS YOUR VALVE VIRTURALLY BECOMES A NEW VALVE.