§250.735. What associated systems and related equipment must all BOP systems include?

An accumulator system, as specified in API Standard 53 (incorporated by reference, see § 250.198). Your accumulator system must have the fluid volume capacity and appropriate pre-charge pressures in accordance with API Standard 53. If you supply the accumulator regulators by rig air and do not have a secondary source of pneumatic supply, you must equip the regulators with manual overrides or other devices to ensure capability of hydraulic operations if rig air is lost;

An automatic backup to the primary accumulator-charging system. The power source must be independent from the power source for the primary accumulator-charging system. The independent power source must possess sufficient capability to close and hold closed all BOP components under MASP conditions as defined for the operation;

At least two full BOP control stations. One station must be on the rig floor. You must locate the other station in a readily accessible location away from the rig floor;

The choke line(s) installed above the bottom well-control ram;

The kill line must be installed beneath at least one well-control ram, and may be installed below the bottom ram;

A fill-up line above the uppermost BOP;

Locking devices for all BOP sealing rams (i.e., blind shear rams, pipe rams and variable bore rams), as follows: