Back in the mid 80’s LB Bentley designed and patented the very first small bore subsea Gate Valves for chemical injection applications on Christmas Trees (XMT’s) and manifolds.  Prior to the introduction of the Bentley small bore valves, it was common practice to utilise larger valves with adapted bores for chemical injection applications.  This meant that the chemical injection valves significantly added to the overall weight and size of the XMT, and so from the desire to reduce the overall bulk and weight the small bore subsea valve was born.

LB Bentley realised that with such a valve the requirement to have robust sealing capability was paramount, so with this in mind the Through Conduit Gate Valve was designed with full metal to metal sealing technology throughout the flow bore, i.e. no polymeric seals are used between the seat and body.  Even to this day this design and sealing technology is truly unique in the market place and with nearly 30 years of field proven success it is still the most reliable and durable small bore subsea valve available.

LB Bentley designed the Through Conduit Gate Valve with a split gate and fixed seat design, as this is the only way that true metal to metal sealing in the valve bore can be achieved.  With the gate to seat and seat to body contact faces always being in contact this ensures that contaminants are prevented from being trapped between the critical sealing surfaces.

Over the years LB Bentley have re-qualified the original design to satisfy the developments in industry requirements.  The valve fully satisfies the requirements of API 6A 20th Edition and API 17D 2nd Edition plus it has achieved a SIL2 rating (assessed by Exida).  Due to its success, the original design has remained practically unchanged over the years.  Certain product developments have been made along with industry requirements, such as being able to offer both manual configurations and hydraulic operation in both ½” and 1” sizes in FF and HH trim, with a broad temperature and pressure range.  Both sizes of actuated valves have been tested and certified for full compliance with API 6A and API17D 2nd edition at an increased number endurance cycles.

Table Through Conduit Article

A full range of accessories and interfaces can be offered to meet customer specific needs, with the option of additional qualification testing should this be required.

1.0in hydraulic with limit switches

The LB Bentley Through Conduit Gate Valve offers a unique product with an unrivalled history of use and a product that fully ensures dependable performance when operating under the most arduous of subsea conditions.  For more information on our valves please visit or contact us direct at

The article appears in the recent ‘Valve User Magazine’ issue 43 <click here>