Untitled - Future Pipe Industries

APPENDIX IV
FLANGE INSTALLATION INSTRUCTIONS
1. Scope
Installation instructions and use of fiberglass ( RTR ) flanges.
Tools
Tools necessary for assembly of Flanges are:
• Ring spanner with required bolt-head size
• Torque wrench with required socket size.
Note: Fiberglass flanges are substantially thicker than steel flanges. The contractor should contact FPI for actual thickness of
flanges supplied to order the correct flange bolt lengths.
Bolts and Nuts
Bolts should be wire brushed and lubricated before being used. Failure to clean the bolts will result in insufficient initial tension
in the flange bolts which could result in movement of the flange during operation conditions. Washers and nuts should
be clean and well lubricated before being used. It is important to use washers with all fiberglass flanges. ALWAYS USE A
TORQUE WRENCH.
CAUTION: Fiberglass flanges must always be installed tension free, therefore flanges must be accurately aligned. Pipelines
must never be pulled by means of the flange bolts. If a fiberglass pipeline is connected to a steel line, this steel line must be
anchored at or near the interface point to prevent any movements or loads being transmitted to the fiberglass line.
2. Connection against raised Face Flange:
Fiberglass flanges are flat faced and must be connected against flat faced flanges. If this is not possible, special precautions
should be taken.
• The gap between the raise face and the flat face must be filled with a stainless steel washer or a hard gasket (e.g. Asbestosfree
CAF-equivalent type) of a thickness equal to:
the raised face ‘t’ + gasket ‘t’ – ⁄”.
• A second alternative is to fit a steel back up ring behind the fiberglass flanges. Through 12” diameter the connection of
fiberglass flat faced flanges is possible provided that the torques is limited. On the fiberglass side of the flange joint the bolts
and nuts must be provided with washers to avoid exceeding the allowable surface pressure.
• When assembling a wafer-type butterfly valve, the bolts should be tightened first by hand. At pressure testing if leakage
occurs, the bolts can be tightened up to the maximum valves.
To avoid over stressing of the flanges, spacers can be placed between the GRP flanges.
3. Tightening sequence of fiberglass flanges
• Tightening of the bolts of a flange connection must be done according to the diagonal sequence shown below.
• Bolts in the flanges must be placed straddle to the centerline unless differently specified.
• The flange must be connected perpendicular on the axis of the pipe. The maximum allowable deviation is as follows:
For pipe diameter through 12” : 1 mm (0.04”)
For pipe diameter 14” through 24” : 2 mm (0.08”)
For pipe diameter 28” mm and larger : 3 mm ( 1/8”)
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