Subsea axial
on-off valve

This subsea on-off valve is specifically suitable for severe duty on-off (upstream) and for quick-acting safety applications (HIPPS). Pressure has no impact on the operating forces and the valve can be opened against full differential pressure.


Subsea qualified

Successful qualification of components, compliance to PR2 testing, 500.000 stroke endurance testing without stem seal leakage, hyperbaric testing.

High reliability

The Mokveld subsea axial on-off valve complies with all requirements according to international safety specifications: IEC 61508, IEC 61511 and API RP 17O, Recommended Practice for Subsea HIPPS. SIL certification issued by TÜV Rheinland emphasises the high reliability of the subsea on-off valve.

No by-pass required

Due to internal pressure balancing of the valve, the operating forces are independent of pressure. Valve can be opened against full differential pressure without damage to sealing. Equalisation by-pass valves are not required.

Axial flow

Streamlined flow path through full-port expanded body avoids turbulence and prevents erosion and vibration.

Low pressure drop

The capacity of the subsea axial on-off valve is extremely high, as a result of which the pressure drop is negligible. Operating costs of pumps and compressors are reduced.

Excellent sealing

In the open position the main seal is protected against erosive flow. The self-energising sealing systems offers reliable bi-directional and bubble-tight shut-off (class VI).

Actuator flexibility

The valve is suitable for a variety of linear subsea actuators. Designed for automatic operation with hydraulic or electric subsea actuators.


The one-piece valve body provides 15% - 60% weight reduction compared to ball or gate valves. This feature is even more attractive combined with spring-opposed actuators.

Product Summary

Type designation
Subsea shutdown valve or isolating valve
Sizes 6" - 24"
Rating API 3000 - 10 000
Other pressure ratings upon request
Water depth
3000 m.
In preference to
Subsea ball valve
Subsea gate valve
Subsea plug valve
Typical applications
Subsea severe duty on-off (upstream)
Subsea quick-acting on-off (HIPPS)
Subsea critical isolation or start-up
Streamlined flow path through full-port expanded body
Streamlined flow path through full-port expanded body
Subsea axial on-off valves as final elements in Subsea HIPPS module
Subsea axial on-off valves as final elements in Subsea HIPPS module

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Special features

  • Custom-designed.
  • Suitable for infrequent use. Operating forces do not increase over time. No sticking.

More information

Subsea products

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Product support

In order to ensure you continue to benefit from valves that offer high capacity and safety as standard, our Product Support team offers a range of services to improve your valves in use and to achieve cost savings.