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BOLTING PROCEDURES FOR FLANGED JOINTS

CONSORCIO OBRAINSA & ASTALDI PROJECT “IRRIGATION MOQUEGUA”

“O-RING GASKET”

0 January 28th

2016 Issued for information L.S. G.M. G.F.

DATE Rev. N° DESCRIPTION Written Checked Approved

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1 - SCOPE This document contains indications relevant to the procedures of bolts installation on flanged joints and to the recommended bolt torque values. 2 - APPLICATION Material: GRP Resin: Vinylester or Isophtalic Installation: Aboveground & Underground Installation 3- REFERENCES ASTM D 5421 4 - BOLTS INSTALLATION To properly install the flange bolts, the following procedure shall be observed: a) Prior to fit-up, clean and lubricate bolts, nuts and washers using a non-fluid thread

lubricant.

b) Install bolts, nuts and washers and tighten the nuts by hand until they are snug.

c) Number the bolts with indelible marker if necessary.

d) Follow the nuts tightening sequence reported on the attached schemes and establish

uniform pressure over the flange face until reaching the torque relevant to the proper

diameter (see the following tables). For tightening operations always use the torque

spanner.

e) For flanges with more than 20 bolts, similar alternating bolts sequences shall be

considered

f) Before starting with the hydrostatic test, the torque of all bolts shall be verified following

the sequence and using the torque spanner.

g) If during hydro test a leakage should occur, an increase of bolt tightening is allowed.

h) Maximum allowable torque value shall not be more than 1,5 times the tabled value.

Cautions: Excess torque could affect the sealing and damage the GRP flanges and check during

operation the flange integrity.

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In case it will necessary to exceed the values indicated in the table, check continuously the

integrity of the flange during assembly and, after test completion, carry out a visual

inspection.

5 - BOLTING SEQUENCES FOR FLANGES COUPLINGS

6 - METHODS FOR REPAIRING

If the above procedures shall be followed, no difficulty should be experienced.

If troublesome problems occur, try to apply the following suggestion:

a) Loose and remove all bolts, nuts, washers and gaskets.

b) Check for alignment of assembly. Rebuild to correct alignment if out of alignment.

c) Check the gasket for damage and, if necessary, replace damaged gasket.

d) Check the surfaces on the counter flanges, valve flanges or lined pipe and fittings

flanges as the case may be. Clean or repair as needed.

e) Repeat the assembling procedure.

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7 - TORQUE VALUES Assumptions: - Gasket type:

a) O-ring gaskets - Bolt torque is based on hydro test pressure

PIPE DIAMETER Drilling  Test Pressure N*m N*m N*m

(mm) Gasket (inches)    barg  (normal) Increase (maximum)

   NP 10 

350 O-Ring 14"

ANSI 150  15  35 17,5 70

400 O-Ring 16"

ANSI 150  15  30 15 60

700 O-Ring 28"

ANSI 150  15  70 35 140

800 O-Ring 32"

ANSI 150  15  100 50 200

900 O-Ring 36"

ANSI 150  15  110 55 220

   NP 6 

500 O-Ring 20"

ANSI 150  9  25 12,5 50

600 O-Ring 24"

ANSI 150  9  40 20 80

700 O-Ring 28"

ANSI 150  9  40 20 80

   NP 16 

900 O-Ring 36"

ANSI 150  24  175 87,5 350

700 O-Ring 28"

ANSI 150  24  105 52,5 210