Apparatus for periodically testing the operation of safety valves

Claim 2

In apparatus for periodically testing the operation of safety valves, on pressure apparatus and vessels, including a stem, said apparatus comprising: (a) a load-bearing structure fixedly arranged with respect to the pressure apparatus, (b) a thrust-generating assembly cooperating with said load-bearing structure, and (c) means for gripping the safety valve being tested, the improvement which comprises, in combination: (i) a steplessly-operable dynamometer device cooperating with the thrust generating assembly and measuring valve-state change-over force applied by the thrust generating assembly to the safety valve being tested, (ii) said load-bearing structure comprising a yoke having a clamping collar, uprights extending substantially perpendicular to the collar, and a cross-member substantially parallel to the collar and inter-connecting the uprights, the thrust-generating assembly being attached to said cross-member, (iii) safety valve gripping means connected to one end of the dynamometer device; said dynamometer device being connected with its other end to the thrust-generating assembly and being located between said thrust-generating assembly and said gripping means, said thrust-generating assembly and said dynamometer device and said gripping means being all aligned with one another and coaxial with said stem of the safety valve.

Claim 3

Apparatus, as claimed in claim 1, including a recorder connected to the dynamometer device for recording signals from the dynamometer device.

Claim 4

Apparatus for periodically testing the operation of safety valves in pressurized apparatus during normal operation of said pressurized apparatus, comprising a load-bearing structure fixedly arranged with respect to the pressurized apparatus at the position of a said safety valve, means for gripping said safety valve, a thrust-generating assembly intercoupling said gripping means and said load-bearing structure and serving to apply thrust which moves said gripping means in a direction relative to said load-bearing structure to open said safety valve, means controlling said thrust-generating assembly firstly to control opening of said safety valve and thereafter gradually reducing thrust to control closing of said safety valve, and a steplessly-operable dynamometer device associated with said thrust-generating assembly to measure valve-state change-over points at unseating and re-seating of said safety valve beng tested.

Claim 5

Apparatus for periodically testing the operation of safety valves in pressurized apparatus during normal operation of said pressurized apparatus, comprising a load-bearing structure fixedly arranged with respect to the pressurized apparatus at the position of a said safety valve, means for gripping said safety valve, a thrust-generating assembly intercoupling said gripping means and said load-bearing structure and serving to apply thrust which moves said gripping means in a direction relative to said load-bearing structure to open said safety valve, means controlling said thrust-generating assembly firstly to control opening of said safety valve and thereafter gradually reducing thrust to control closing of said safety valve, and a steplessly-operable dynamometer device associated with said thrust-generating assembly to measure valve-state change-over points at unseating and re-seating of said safety valve beng tested.

Claim 6

Apparatus for periodically testing the operation of safety valves in pressurized apparatus during normal operation of said pressurized apparatus, comprising a load-bearing structure fixedly arranged with respect to the pressurized apparatus at the position of said safety valve, means for gripping said safety valve, a thrust-generating assembly intercoupling said gripping means and said load-bearing structure and serving to apply thrust which moves said gripping means in a direction relative to said load-bearing structure to open said safety valve, means for controlling said thrust-generating assembly firstly to open said safety valve and thereafter gradually to reduce thrust to allow said safety valve to close itself, and a steplessly operable dynamometer device associated with said thrust-generating assembly to measure valve-state change-over points at unseating and re-seating of said safety valve being tested, further comprising means for measuring pressure in said pressurized apparatus, and means connected to said dynamometer device and said means for measuring pressure for recording said valve changeover points and a related output from said means for measuring pressure.

Claim 7

Apparatus for periodically testing the operation of safety valves in pressurized apparatus during normal operation of said pressurized apparatus, comprising a load-bearing structure fixedly arranged with respect to the pressurized apparatus at the position of said safety valve, means for gripping said safety valve, a thrust-generating assembly intercoupling said gripping means and said load-bearing structure and serving to apply thrust which moves said gripping means in a direction relative to said load-bearing structure to open said safety valve, means for controlling said thrust-generating assembly firstly to open said safety valve and thereafter gradually to reduce thrust to allow said safety valve to close itself, and a steplessly operable dynamometer device associated with said thrust-generating assembly to measure valve-state change-over points at unseating and re-seating of said safety valve being tested, further comprising means for measuring pressure in said pressurized apparatus, and means connected to said dynamometer device and said means for measuring pressure for recording said valve changeover points and a related output from said means for measuring pressure.

Claim 8

In apparatus for periodically testing the operation of safety valves, on pressure apparatus and vessels, including a stem, said apparatus comprising: (a) a load-bearing structure fixedly arranged with respect to the pressure apparatus, (b) a thrust-generating assembly cooperating with said load-bearing structure, and (c) means for gripping the safety valve being tested, the improvement which comprises: (i) a steplessly-operable dynamometer device cooperating with the thrust-generating assembly and measuring valve-state change-over force applied by the thrust-generating assembly to the safety valve being tested, (ii) said load-bearing structure comprising a yoke having a clamping collar, uprights extending substantially perpendicular to the collar, and a cross-member substantially parallel to the collar and interconnecting the uprights, the thrust-generating assembly being attached to said cross-member, (iii) safety valve gripping means connected to one end of the dynamometer device, said dynamometer device being connected with its other end to the thrust-generating assembly and being located between said thrust-generating assembly and said gripping means, said thrust-generating assembly and said dynamometer device and said gripping means all being aligned with one another and coaxial with said stem of the safety valve, (iv) a recorder connected to the dynamometer device for recording signals from the dynamometer device, (v) a displacement movement measuring device comprising a sleeve adjustably secured to one of said uprights of said yoke, said sleeve having a pivot, a rod mounted to said sleeve pivot and contacting with one of its ends said stem of the safety valve, a displacement movement transducer connected to said recorder for passing to said recorder signals corresponding to displacement movements of said valve stem, said transducer being connected to the other end of said rod.

Claim 9

In apparatus for periodically testing the operation of safety valves, on pressure apparatus and vessels, including a stem, said apparatus comprising: (a) a load-bearing structure fixedly arranged with respect to the pressure apparatus, (b) a thrust-generating assembly cooperating with said load-bearing structure, and (c) means for gripping the safety valve being tested, the improvement which comprises: (i) a steplessly-operable dynamometer device cooperating with the thrust-generating assembly and measuring valve-state change-over force applied by the thrust-generating assembly to the safety valve being tested, (ii) said load-bearing structure comprising a yoke having a clamping collar, uprights extending substantially perpendicular to the collar, and a cross-member substantially parallel to the collar and interconnecting the uprights, the thrust-generating assembly being attached to said cross-member, (iii) safety valve gripping means connected to one end of the dynamometer device, said dynamometer device being connected with its other end to the thrust-generating assembly and being located between said thrust-generating assembly and said gripping means, said thrust-generating assembly and said dynamometer device and said gripping means all being aligned with one another and coaxial with said stem of the safety valve, (iv) a recorder connected to the dynamometer device for recording signals from the dynamometer device, (v) a displacement movement measuring device comprising a sleeve adjustably secured to one of said uprights of said yoke, said sleeve having a pivot, a rod mounted to said sleeve pivot and contacting with one of its ends said stem of the safety valve, a displacement movement transducer connected to said recorder for passing to said recorder signals corresponding to displacement movements of said valve stem, said transducer being connected to the other end of said rod.

Claim 10

Apparatus, as claimed in claim 5, wherein said pivot is on a bracket displaceable sideways with respect to said sleeve by screw-threaded means.

Claim 11

Apparatus, as claimed in claim 6, further comprising a gauge fitting on said pressure vessel, and a pressure transducer mounted on said gauge fitting and connected to said recorder.