Bolted closures are the most popular closure design specified in pressure vessels. They are a more traditional method, compared to the complex range of closure types now available but are still a good choice, as they are relatively low cost.

They are easy to handle, simple to operate and their minimal design provides great flexibility; allowing the customer to configure the equipment to their individual project needs.

Various types of seal solutions can be fitted, to suit the application requirements. These include low cost standard rubber O rings; more complex bespoke engineered plastic seals and even metal to metal type sealing solutions (such as BX rings or C-rings.)

KW Designed Solutions bolted closure pressure vessels, are supplied with operating pressures of up to 2069 bar and temperatures ranging from -196°C to +650°C.


  • Material of Construction: Stainless Steels, Exotic Steels (Hastelloy, Inconel), Carbon & Alloy Steels
  • Multi-Penetration
  • Opening/Closing Times: From 5 Mins to 1 Hour Depending on Size & Number of Bolts (Bolt Tensioning Devices Are Available for High Torque Applications)
  • Pressure Ratings: 6 Bar to 2069 Bar
  • Seal Types: O Seals, PTFE, Gaskets, Metallic Seals (BX Rings, C-Rings)
  • Size: Between Ø50mm to Ø1000mm Bore & Depths of 100mm to 2000mm
  • Temperature: -196°C to 650°C
  • Volumes: 0.25 Litre to 1500 Litre


  • Can Be Supplied with Any Type & Size of Port Configuration, Dip Tube or Thermowell
  • Ideal for Smaller Bench-Top Applications
  • Low Cost Manufacture
  • Robust Sealing Solution When Correctly Specified for Application
  • Simple & Easy to Use
  • Valves & Fittings

Applications & Customer Uses

Our bolted closure pressure vessel is a popular choice with customers who work within the scientific, materials testing & research industry.

To provide the confidence that the vessel will remain pressurised, for the entire duration of demanding testing applications; we utilise torqued up bolts and clamp the closure seal.

The bolted closure is typically associated with reactor pressure vessels and autoclaves; providing a robust sealing solution. This gives the customer the ability to conduct high elevated temperature testing, for durations of up to and over 3 months, where immediate access to the vessel is not required.

Project Examples

Pressure vessel for testing subsea electrical connectors

This pressure vessel is configured horizontally and used to conduct qualification testing & production FATs on electrical and fiber-optic connector systems, for subsea power and communications.

  • Pressure rating: 550 bar
  • Size: Ø617mm x 6000mm long
  • Temperature: -10°C to +200°C
  • Volume: 1800 litres

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Pressure Testing Wellhead Pressure & Temperature Sensors

We designed and manufactured this pressure vessel containment rig, to optimise the throughput of wellhead pressure and temperature sensor production testing.

  • Pressure Rating: 2069 Bar
  • Size: Ø57mm X 350mm Depth
  • Temperature: Ambient
  • Volume: 4 Litres

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Pressure Vessel Testing Valve Seals

Designed for hydrostatic pressure testing of a 20” NB face seal for use in subsea valves.

  • Pressure Rating: 525 Bar
  • Size: Ø57mm X 350mm Depth
  • Temperature: -10°C to +50°C
  • Volume: 4 Litres

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