Bolted Closure Pressure Vessels

Bolted Closure Vessels are widely used in pressure vessel supply and probably the most traditional design used. The Bolted Closure in some cases is a preferred choice over some of the more complex types of closures on offer due to their simplicity and relatively low cost. They are easy to handle and operate and though of a simple design, they offer great flexibility allowing the customer to configure as necessary for any specific requirement.

The Bolted Closure allows the fitting of many types of seal solutions depending on the users’ applications; from low cost standard rubber O rings to 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 range from -196°C to +650°C.

Bolted Closure Vessels


  • Pressure ratings: 6 bar to 2069 bar
  • Temperature: -196°C to 650°C
  • Size: Between Ø50mm to Ø1000mm bore and depths of 100mm to 2000mm
  • Volumes: 0.25 litre to 1500 litre
  • Seal Types: O seals, PTFE, gaskets, metallic seals (BX Rings, C-Rings)
  • Material of construction: Stainless steels, exotic steels (Hastelloy, Inconel), carbon and alloy steels
  • Opening/closing times: from 5 mins to 1 hour depending on size and number of bolts, (Bolt Tensioning devices are available for high torque applications)
  • Multi-penetration


  • Simple and easy to use
  • Low cost manufacture
  • Robust sealing solution when correctly specified for application
  • Ideal for smaller bench-top applications
  • Can be supplied with any type and size of port configurations, dip tubes, thermowells, valves and fittings

Applications and Customer Uses

The KW Designed Solutions Bolted Closure Pressure Vessel has proved to be a popular choice for our customers who work within the Scientific, Materials Testing & Research industry sectors.   Using torqued up bolts and clamping of the carefully selected closure seal provide the customer with the confidence that the vessel will remain pressurized for the duration of even the most demanding testing applications.

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

Project Examples

Pressure vessel for testing subsea electrical connectors

Pressure testing subsea electrical and fibre-optic connector systems (Ref: SO575, Equip No. 2149)

Configured horizontally, this pressure vessel is used for carrying out qualification testing & production FATs on electrical and fiber-optic connector systems for subsea power and communications.

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

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Pressure testing wellhead pressure and temperature sensors

Pressure testing wellhead pressure and temperature sensors (Ref: SO207, Equip No. 2003)

This pressure vessel containment rig was designed to optimise the throughput of wellhead pressure and temperature sensor production testing.

  • Pressure rating: 2069 bar
  • Temperature: Ambient
  • Size: Ø57mm x 350mm depth
  • Volume: 4 litre

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Pressure vessel testing valve seals

Pressure testing seals for use in subsea valves (Ref: SO295, Equip No. 2039)

Designed for hydrostatic pressure testing of a 20” NB face seal for use in subsea valves for the oil and gas industry.

  • Pressure rating: 525 bar
  • Temperature: -10°C to +50°C
  • Size: Ø57mm x 350mm depth
  • Volume: 4 litre

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kw designed solutions

Tel: +44 (0) 1257 474 507

KW Designed Solutions Ltd, KW Group, Drumhead Road, Chorley North Business Park, Chorley, Lancashire PR6 7DE. United Kingdom.

Designed and manufactured in the UK Designed and manufactured in the UK.