CONNECTIONS PIPE TO EQUIPMENT

Piping shall be erected and supported in a manner that will not put undue strain on equipment such as compressors, engines, pumps, vessels and heat exchangers. Cold pull shall be to Company’s approval.

The following procedure shall be observed:
·            Initially, piping shall be attached to the equipment using finger tightened bolts
·            Flat face flanges and full face gaskets shall be used on piping connecting to equipment with flat face flanges only.
·            Flanges shall be checked to ensure that no strain is placed on the equipment. If the pipe is not in correct alignment it shall be removed and corrected. The correction in alignment shall not be made while the pipe is connected to the equipment.  Heating of piping to correct misalignment shall not be permitted.

·            Finally tighten bolts to correct torque.

·            All brazed aluminum heat exchanger misalignment tolerances, bolt torque values and flange tightening procedures shall be strictly observed. Hammer wrenches shall not be used. Company shall witness all brazed aluminum heat exchanger flange bolt-ups.

Cold pulls shall be approved by Company.

The following procedure shall be applied for the alignment of flanges to rotating equipment:
·            Align pipe work to equipment flanges to within the more stringent of either the manufacturer’s tolerances or ASME B31.3. Adjust pipe support where necessary.

·            Flange faces shall be parallel within 1/16” measured across any diameter.

·            Bolt up piping to equipment flanges and torque the bolts to the specified tension.

·            Check the coupling alignment during the bolting and tensioning of the pipe flanges to the equipment flanges. The bolting up and tensioning of the flanges shall not affect the coupling alignment between the driver and driven equipment.

·            Check setting of pipe support.

·             Finally tighten bolts to correct torque.
Flange Connections

Flange connections shall be made up as follows:

·            Clean protective grease from flange gasket faces and position for bolt up.  Flange faces shall be parallel and aligned axially in the horizontal and vertical plane to the tolerances. Position gasket and install bolts and nuts to hand tight.

·            All bolts for flanged connections require extreme attention in assembly to ensure uniform loading on the gasket surfaces.  Non uniform bolt loading, dirt at the mating surfaces or scratched flange surfaces shall be subject to release and flange joint re-assembly or flange face redressing.

·            Regardless of the scheme selected for flange joint assembly, i.e. gauge between flanges, torque wrench or bolt elongation, it is important to tighten uniformly and not prematurely set the gasket.  Hand tighten all nuts first, and then gradually tighten opposite nuts on the flange.  Do not bring a single nut to full tightness before the others have been carefully stepped up toward this final position.

·            Flange bolt and stud threads shall protrude a minimum of ¼ inch or two full thread pitches, whichever is the greater, past the nut. Extremely long bolt projection will not be accepted unless required for hydraulic tensioning.  Uniformity of bolt projection through the nuts of stud bolts shall be observed.

·            New gaskets shall be used whenever a set of flanges is broken apart and then re-connected.
FRP Flange Connections

All flanged joints shall be uniformly tightened and shall be torque no more than the pipe manufacturer’s recommended limit.

FRP flanged joints shall be fully tightened, with the pipe support to FRP pipe clamps loose.

The FRP pipe clamps shall be tightened only once final flange bolting shall have been completed.

Washers shall be used at all bolted connections where all FRP flat faced flanges mate together or with wafer type valves. Flat faced flanges shall not be used with raised faced flanges.

The specification break between carbon steel and FRP piping shall utilize flat faced carbon steel flanges.