wedge gate valve

Babcock Valve’s pressure seal bonnet on a wedge gate valve


Our Valves can adopt pressure seal bonnets to allow high pressure service, typically in excess of 15 Mpa (2250 psi). The main feature about the pressure seal bonnet is that the body-bonnet joints seals improves as the internal pressure in the valve increases, compared to other constructions where the increase in internal pressure tends to create leaks in the body-bonnet joint.

The seal is achieved from the pressure exerted by the fluid flowing trough the valve as follows:

Internal pressure forces the bonnet upwards against the gasket, creating forces in the contact areas between the gasket and the bonnet.

Leaks most commonly arise at the contact surface between the gasket and the body. The area where the body is in contact with the joint is covered by stainless steel, improving surface’s quality and avoiding corrosion issues.

Babcock Gate Valves

Babcock Gate Valve pressure seal bonnet detail



  • Ends to end dimensions are for short pattern, long patterns are available on request.
  • The valve weight is for Butt Welding ends.
  • Dimensions in mm. and weights in kg.
  • Dimensions not shown for classes 2500 and 4500 to customer requirements