255.161 Supports and anchors.

(a)Each pipeline and its associated equipment must have enough anchorage or support to:#

(1)prevent undesigned-for strain on connected equipment;#

(2)resist longitudinal forces caused by a bend or offset in the pipe; and#

(3)prevent or damp out excessive vibration.#

(b)Each exposed pipeline must have enough support or anchorage to protect the exposed pipe joints from the maximum end force caused by internal pressure and any additional forces caused by temperature expansion or contraction or by the weight of the pipe and its contents.#

(c)Each support or anchor on an exposed pipeline must be made of durable, non-combustible material and must be designed and installed in compliance with the following:#

(1)Free expansion and contraction of the pipeline between supports or anchors may not be restricted.#

(2)Provision must be made for the service conditions involved.#

(3)Movement of the pipeline may not cause disengagement of the support equipment.#

(d)Each support on an exposed pipeline operated at a stress level of 50 percent or more of SMYS must comply with the following:#

(1)A structural support may not be welded directly to the pipe.#

(2)The support must be provided by a member that completely encircles the pipe.#

(3)If an encircling member is welded to a pipe, the weld must be continuous and cover the entire circumference.#

(e)Each underground pipeline that is connected to an unyielding line or other fixed object must have enough flexibility to provide for possible movement, or it must have an anchor that will limit the movement of the pipeline.#

(f)Each underground pipeline that is being connected to new branches must have a firm foundation for both the header and the branch to prevent lateral and vertical movement.#