Threaded Closure Pressure Vessels

The KW Designed Solutions Threaded Closure Pressure Vessel utilises a two piece closure system consisting of a plug and captive lock ring.

The closure is easy to handle, but safe, reliable and robust in operation when quick and easy access into the pressure vessel is required; offering many advantages over a typical Bolted Closure.

Generally used for small to medium sized pressure vessels, they are an economical alternative to KW Designed Solutions range of quick-acting closures, utilising a unique smooth-form thread and low friction coating that allows effortless opening and closing of the vessel without the need for tooling.

The Threaded Closure allows the fitting of low cost elastomeric O-Rings and Back-up Ring combinations or engineered plastic seals rather than metal to metal seals, making the pressure vessel more cost effective and cheaper to service & maintain. 

Used in the vertical orientation these vessels require minimal shop floor space.  They can be supplied in horizontal orientation with the addition of vessel and closure support frames incorporated into the design to ensure that closure alignment with the vessel body is maintained.

Threaded Closure Vessels


  • Pressure ratings: 50 bar to 3000 bar
  • Temperature: -50°C to 250°C
  • Size: Ø25mm to Ø400mm bore and depths of 50mm to 2.5m
  • Volumes: 50 ml to 250 litre
  • Seal Types: O-Ring & Back-up Ring, PTFE, Spring seal, bespoke design
  • Material of construction: Stainless steels, exotic steels (Hastelloy, Inconel), carbon and alloy steels
  • Vessel Configuration: Vertical or Horizontal with a single Closure and blind bore or with dual Closures


  • Quick & easy access into pressure vessel without the need for tooling
  • Opening & closing from 1 minutes to 10 minutes depending on size and pressure rating
  • Low cost
  • Sealing elements easy to service & maintain
  • Smooth-form thread & low friction coating helps to drive seal into place with minimal effort & wear

Applications and Customer Uses

The KW Designed Solutions Threaded Closure Pressure Vessel has proved to be a popular choice for customers in various industries who require simple, economically priced vessels that still allow relatively quick and easy access.

Customers in the Oil & Gas and Subsea sectors use Threaded Closure Pressure Vessels for Product Verification, Factory Acceptance Testing (FAT) and Production Testing of subsea electrical components, hoses, cables, penetrators and valve seal arrangements.

The Closure is also a popular choice for Customers from Scientific and Material Research industries working at pressures up to 400 Bar at 200°C as well as those needing smaller bench top Reactor Vessels, (50ml to 1 litre) for use in Laboratories up to 200 bar at 250°C.

Project Examples

Autoclave corrosion testing

Autoclaves for HPHT corrosion testing (Ref: SO476, Equip No. 2092)

The Autoclaves are used for carrying out long term corrosion testing on clients test samples. Tests conditions are generally High pressure high temperature HPHT testing whilst using various media. 

  • Pressure rating: 440 bar
  • Temperature: 0°C to +200°C
  • Size: Ø192mm x 300mm depth
  • Volume: 10 litre

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Pressure vessel for subsea power systems research and development

Pressure vessel for subsea power systems research and development  (Ref: SO477, Equip No. 2097)

This special purpose pressure vessel allows in-house testing to be conducted for a joint industry project (JIP) developing deepwater subsea power and control technologies for the development of next-generation subsea power systems. 

  • Pressure rating: 550 bar
  • Temperature: -40°C to +200°C
  • Size: Ø300mm x 600mm depth
  • Volume: 42 litre

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Pressure vessel for testing underwater positioning transponders and transceivers locating subsea equipment

Pressure vessel for testing underwater positioning transponders and transceivers   (Ref: SO153, Equip No. 1093)

Special purpose pressure vessel for hydrostatic testing underwater positioning transponders and transceivers used for the accurate positioning and location of subsea equipment both towed and autonomous, subsea cable and pressure housing assemblies.

  • Pressure rating: 490 bar
  • Temperature: Ambient
  • Size: Ø350mm x 1400mm depth
  • Volume: 140 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.