assurance approvals for design and
manufacture.
Running in parallel with these assessments, equipment manufacturers also
subject their products to the test procedures required for end-user approvals in
specific markets and industrial disciplines. In these areas there have been
significant market-led increases in
activity in recent years.
In addition to the hyperbaric testing
of subsea actuators and performance
verification of gas-over-oil actuators
mentioned later in this article, testing
programs in recent years have expanded
to include specific tests such as:
IP66M/67M, dust, water jet,
immersion and deluge testing of
pneumatic actuators
Shell qualification for hydraulic
and pneumatic actuators
Transco qualification for hydraulic
actuators
HIPPS (high integrity pressure
protection systems) qualification
for control systems
GOST Russian Certificate of Conformity and Federal Use Permit
ABS (American Bureau of Shipping)
In one API test performed by a major
equipment manufacturer, a scotch-yoke
hydraulic actuator with ROV (
remote-operated vehicle) override was operated
in a hyperbaric chamber under an external pressure of 3600 psi (240bar-g) to
represent the submerged qualification
depth of 2,400 meters over a period of
six weeks. The actuator was selected as a
representative sample of all the company’s subsea actuators for the purpose of
the testing, which was witnessed by a
third-party inspector. The severity of the
testing reflects the crucial nature of subsea actuator duties and the increasing
depths at which actuators are expected to
perform as exploration moves into new,
more remote offshore fields.
In the ST-028 hyperbaric test a similar hydraulic actuator fitted with a
limit switchbox was subjected to cyclic
testing to prove its suitability for sub-
Hyperbaric chamber for subsea actuator test
merged installation at a depth of 45
meters. The witnessed testing included
pressurizing the switchbox with air at
75 psi (5bar-g) without any sign of
leakage or bubbles, static torque and
cycle testing of the actuator at ambient
These are in addition to ATEX explosion-proof certification, PED (European
Pressure Equipment Directive) approval
and SIL (safety integrity level) assessments that also apply to pipeline actuation products.
Subsea Actuators, Testing
In-depth
Subsea valve applications, which often
involve vital fail-safe and associated
safety-related duties, represent an area
of technology demanding the very high-
est levels of quality and product integri-
ty to ensure reliable long-term perform-
ance. It may be prudent to not only test
to API (American Petroleum Institute)
qualification but also to achieve third-
party-witnessed hyperbaric approval to
the international qualification proce-
dure ST-028.
