Drill stem testing tools
Super Safety Valve
The Super Safety Valve is controlled by two hydraulic lines and contains a chemical injection port. It is designed to
close by spring force but has a nitrogen charge chamber to quicken the closing time. This feature gives the valve the
ability to cut wireline and coiled tubing without the addition of balance line pressure. The valve is held open by
maintaining hydraulic control pressure on the control line. The nitrogen charge chamber and the balance line
chamber are the same chamber. The nitrogen pressure acts directly on the operating piston and a floating check
valve keeps the nitrogen from escaping from the chamber into the balance line. The check valve floats on the surface
of the water (or hydraulic fluid) as fluid is pumped into the chamber. When the fluid is removed, the floating check valve
sets down on the seat and seals the nitrogen charge in the chamber.
Typically, the nitrogen charge chamber of the valve is charged with nitrogen to 1000 to 1500 psi. This charge is sufficient to cut 7/32 inch monoconductor cable, but it is not adequate to cut coiled tubing. The valve can
be charged with nitrogen sufficient to cut coiled tubing, but this raises the required hold open pressure. The tool is
capable of cutting 1.50 inch OD x 0.125 inch wall thickness coiled tubing by application of balance line pressure. The
hold open pressure varies with well conditions; however, it is roughly 2.5 times the nitrogen charge pressure.
All lines on the valve will hold 10000 psi, but a differential pressure between the control and balance line should not
exceed 3000 psi under normal circumstances (control line being higher). This prevents the application of excessive
stress to the ball. (10000 psi in the balance line with no control line pressure is within operational limits.)
Typically, the valve is run into the BOP where the valve controls the tubing area while the BOP pipe ram seals off the
Internal pressure strength
External pressure strength
5 3/4-4AS.B 5"-4ACME.B
ZZ Top Oil Tools Co.,Ltd, with the professional technical team, specialized in providing cost-effective oilfield
equipment, and at the moment ZZ TOP invested in two sub-factories, one is for Drill stem testing tools
and some downhole tools, The other one is for wellhead equipment.
As one group, ZZ TOP provides the clients highly efficient & expertized service as well as more comprehensive
products to meet the customers' requirements during the work, and insists on "Traceability, Serialization" for
each tools and related parts.