API RP 64:2001(2012) pdf download
API RP 64:2001(2012) pdf download.Recommended Practice for Diverter Systems Equipment and Operations.
5.8.3 Closing Unit Backup System
A secondary means (backup system) should he employed to permit sequencing the div ener system should the primary dosing system become inoperatIve. This may be complished by alternative pump system capacity. separate isolated accumulator capacity, nitrogen backup capacity, or other means. The backup system should be automatically or selectively available on demand. The backup system should be included in diverter system testing and maintertince procedures.
5.8.4 Accumulator Recharging Capability
The pump system(s) should be capable of recharging the primary diverter control system accumulators to lull system design pressure within five minutes or less after one complete divert mode operation of the disener control system. This shoukl be verified by fully charging the accumulators, isolating the pumps from service, and sequencing the divert functions using only the accumulators.
5.8.5 Pump Systems
A pump system consists of one or more pumps. Each pump system I primary and secondary) should base independent power sources, such as electricity or air. ‘The same pump system may be used to provide power fluid to the HOP stack and the diverter system. Power for the closing unit pump(s) should be available to the accumulator unit at all times, such that the pump(s) automatically start when the closing unit manifold pressure has decreased to less than 90% of the accumulatcw operating pressure. Similarly, the pumpis) should automatically stop when the full design accumulator charging pressure is reached.
5.8.5.1 Pump Pressure
Each closing unit should be equipped with a pump(s) that provides a discharge pressure at least equivalent to the worting pressure rating of the closing unit.
5.8.5.2 Pressure Protection
Each pump system should be protected from over pressurization by a minimum of two devices to limit the pump discharge pressure. One device, normally a pressure limit switch, should lirtiit the pump discharge pressure so that it will not exceed the working pressure rating of the divcrter control system. The second device, normally a relief valve. should be sized to reline at a flow rate at least equal to the designed flow rate of the pump systems and should be set to relieve at not more than 10% over the control unit working pressure. These pressure limiting devices should be installed directly in the control system supply line to the accumulators and should not have isolation valves or any other mcan that could defeat their intended purpose. If isolation valves are desired to permit service sir testing of the pressure-limiting derice. those valves should he car-sealed open. Rupwre disc(s) or relief valve(s) that do not automatically reset are not recommended.
5.8.6 Control System Valves, Fittings, Lines, and Manifolds
Additional information and rcconuncndations for closing units are ftsind in API RP 53. That document describes recommended practices tir surface and subsea installations.
5.8.6.1 Valves, Fittings, and Other Components
The discrtcr control system should he equipped:
I. With a full-opening valve into which a separate fluids pump can be easily connected.
2. To allow isolation of the pumps and accumulators horn the manifold and annular control circuits, for maintenance and repairs.
3. With pressure gauges to indicate: a) accumulator pressure. b) regulator manifold pressure. c) annular pressure. and d) air pressure. Control system pressure gauges should be calibrated at least once esei year.
4. With necessary pressure regulators to permit rn.inual control of system csflhlponcnt% within their rated working pressure.
I With clearly marked controls to indicate which valve is operated and the position of the valve.
