Pressure seal Gate Valves

The high pressure gate valve, also called pressure seal gate valve, is designed and manufactured according to ASME B16.34, API600, and the valve has the characteristics of beautiful appearance, compact structure and reliable seal. It is suitable for various pipelines of Class900 to Class4500.


Operating principle pressure gate valve:
Before the high pressure gate valve is boosted, turn the tightening bolt to raise the bonnet, so that the initial formation between the bonnet, the segment ring, and valve body created sealing condition – preload pressure on the sealing surface. When the media pressure increases, the sealing pressure between the bonnet, segment, valve body increases gradually with the increase of medium pressure. In self-tight sealing, the working seal pressure on the sealing surface is synthesised by two parts: one is the pre-tight seal pressure, and the other is the pressure formed by the pressure of the medium. It should be emphasised that: the media pressure in a self-tightening seal always tends to increase the preload seal pressure to increase sealing performance. The higher the media pressure, the greater the operating seal pressure and the better the sealing performance.


The main features of the high pressure gate valve:
①    The self-sealing structure can make the connection between the valve body and bonnet of the high-pressure valve tightly structured, labor and material saving, safe and reliable.
②    The high pressure gate valve uses a combined structure at the bonnet pressure self-sealing, to achieve a linear seal, while its seal ring uses Austenitic stainless steel, anti-corrosion, extends the life of the use, thus ensuring that the valve seal is not leaking under high pressure difference.
③    When the high pressure gate valve is in the 2500LB and above, the inner cavity of the valve body and the contact area of the sealing ring are welded with stainless steel material to avoid the valve body sealing area being eroded by air and water under high pressure difference, which may cause pitting leakage, thus ensuring the safe and long-term operation of the valve.


Self-sealing structure of the high pressure gate valve:
The pressure seal gate valve uses a sealing structure combined with the packing outer seal and the internal pressure self-sealing at the stem seal to ensure that the medium does not leak. The outer seal of the stem is filled with polytetrafluorene or O-ring packing, which is pressed tightly with packing gland. Under the action of media pressure, the upward pressure is generated, the greater the pressure of the medium, the greater the sealing force, this structure is suitable for high media.

Gate Valves


Gate Valves – Pressure-seal

Size 3″ to 42″ (80 mm to 1050 mm)
ASME Class Class 600 to 2500
Design Standard ASME B 16.34, API 600

Beyond Standards:

  • Pressure-seal Gate Valve design conforms to ASME B 16.34.
  • The design was successfully validated by conducting in-house High Pressure High Temperature (HPHT) Gas Tests on ultra-high pressure valve prototypes.
  • Flow Interruption Test successfully conducted on 8″ Class 600 Pressure-seal Gate Valve suitable for Main Stream Isolation Valve (MSIV) service in nuclear power plants – at Areva, Germany.
  • Fugitive Emission – 14″ Class 2500 Pressure-seal Gate Valve (test pressure of 431 bar at ambient and 289 bar at 400 degree C) has been tested successfully as per ISO 15848-1, endurance Class CO2 and Tightness Class BH
  • CE Marking – Meets requirements of Pressure Equipment Directive 2014/68/EU, Annexure III, Module H
  • Atex – Meets requirements of Atex Directive 94/9/EC (ATEX), category 2 non-electrical equipment
  • SIL3 Safety Integrity Level for Automated Valves
  • Pressure-seal Gate Valves (up to Class 2500) used in Oil & Gas industry tested to ISO 15848-1 Class BH
  • Pressure-seal Gate Valves successfully tested to Shell Design Validation Test 77/300 and witnessed by Shell Inspectors

Features that Add Value:

  • Valves in intermediate classes reduce total cost of ownership
  • Pressure-Seal mechanism utilizes line pressure to enhance seal; ensures sealing integrity at higher operating pressures.
  • Higher hardfacing thickness (3 mm) to ensure consistent hot hardness
  • Disc guides hardfaced for longer life
  • Customised deposition process in F91/ C12A valves to avoid delamination of hardfaced surfaces
  • Live loading of bonnet bolts for F91/ C12A valves
  • Special high purity graphite packing (seven rings) provided for pressure rating > Class 2500 in Power applications
  • Live loading of bonnet bolts and gland bolts for all valves in F91/ C12A construction

Versatile Solutions:

  • Available in a cast and forged steels and exotic metallurgies for a wide variety of applications
  • By-pass arrangement provided for over-pressure protection based on customer requirement
  • Accessories: Heat Dissipation Bonnets, Dashpot Arrangement, Limit Switches, Extension Spindles and Position Indicator
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