Boltright Tightening Procedure 20-900

BOLTRIGHT Tightening Procedure

BOLTRIGHT RESULTS SUMMARY and

TIGHTENING PROCEDURE

Date: 06/24/2009 at 03:31 PM

Bolt Tension Procedure for 20" # 900 Flange Name: Saad Abou-Zeid

Organisation: TRO

Joint Tag:

Remarks:

Flange and Gasket Details Flange Standard: ANSI

Flange Class: 900

Flange Nominal Size: 20

Operating Temperature: 20 C

Design Pressure: 153 bar (2220 psi)

Test Pressure: 230 bar (3330 psi)

Number of Bolts in Flange: 20

Bolt Thread Size: 2 - 8 UN

Bolt Material: ASTM A193 - B7

Bolt Minimum Yield Strength: 724 N/mm² (105000 Lbf/in²)

Gasket Type: Spiral Wound Gasket

Gasket Material: Graphite or Soft Steel

Gasket m Factor: 2.50

Gasket y Factor: 69 N/mm² (10000 Lbf/in²)

Effective Gasket Seating Width: 8.98 mm (0.354 in)

Gasket Load Reaction Diameter: 553.5 mm (21.79 in)

Tensioning Procedure This tensioning procedure is a guide and may be needed to be adapted to suit the specific situation and circumstances. This procedure is designed to produce a residual load in each bolt of 402.4 kN (90475 lbf) . This represents 31% of the minimum yield strength of the bolt. The bolts will be tensioned during the tightening process to a higher load initially to allow for elasticity effects. The maximum loading sustained by the bolts during the tightening process represents 49%. of their minimum yield strength. Prerequisites: All personnel involved in implementing this procedure are competent in the use of the tightening equipment and joint tightening procedures. If assistance is needed, please contact Hi-Force. Important Note: This tensioning procedure is based upon using the Hi-Force hydraulic tensioner model number STS4-200 and a Pressure A = 746 bar (10818 psi) and a Pressure B = 597 bar (8655 psi) A. Pre-Bolting Inspection A.1 Gasket. Make sure the material is as specified, look for any possible defects or damage in the gasket such as folds or creases. A2. Flange. Inspect the gasket seating surfaces. Check for corrosion pitting, cracks, and tool marks. Any radial tool marks can directly lead to leakage regardless of the gasket material or the amount of bolt tightening. Make sure that the gasket seating surface is appropriate for the type of gasket being used. Check the areas on the flange file:///C|/Program Files/Hi-Force/BoltRight/Tensioning Procedure.htm (1 of 2)6/24/2009 3:31:21 PM

BOLTRIGHT Tightening Procedure

where the nuts will seat. These should be flat and free from pitting and excessive wear. A3. Flange Alignment. It is important that the flange faces are parallel and aligned. The flange bolt holes should be lined up so that the bolts will not be bent when tightened. A4. Bolts. The bolt material specified is ASTM A193 - B7 and the thread size is 2 - 8 UN . Check each bolt to ensure that this is the case and that each bolt, nut and washer (if used) do not shown signs of corrosion, damage or excessive paint. Note: Any defects noted during the inspection must be rectified prior to starting the tensioning procedure. B. 25% Tensioning Procedure B1. Square up the Flanges. Hand tighten the bolts to square up the joint. Ensure that the flange faces are kept parallel to each other by partially tightening the bolts so that there is metal to metal contact around the full periphery of the joint. B2.1 Tensioning. The 20 bolts in the flange are to be tightened using a 25% tensioning procedure i.e. tensioners will be fitted to 5 bolts eqi-spaced around the flange. These are tightened to a high pressure (Pressure A) before the next 5 bolts are tightened to this pressure (Pressure A). This is repeated until all the 20 bolts in the flange have been tightened. A "break loose" pressure is then determined for the tightened bolts which should be greater than Pressure B (which is lower than the original tightening Pressure A). The sequence and pressures applied are critical to achieving a leak free joint, carefully follow the instructions detailed below: B2.2 Tensioner Installation. Fit the hydraulic tensioners (Hi-Force Model Number STS4-200) to 5 bolts eqi-spaced around the flange. B2.3 Pressure A Tensioning. Apply Pressure A i.e. 746 bar (10818 psi) and tighten the nuts using a tommy bar. Release the pressure and remove the tensioners from the bolts. Place the tensioners on the next 5 bolts ensuring that the tensioners are eqispaced. Apply Pressure A i.e. 746 bar (10818 psi) and tighten using a tommy bar. Repeat this procedure until all 20 bolts have been tightened using Pressure A. B2.4 Break Loose Tensioning Check. Transfer the hydraulic tools back to the 5 bolts that had been first tightened. Increase the tensioner pressure slowly whilst attempting to rotate the tommy bar in the socket in the loosening direction of the nuts. Turn the pump off as soon as the nut first starts to rotate and make a note of the pressure (the "break loose" pressure). If this is equal to or greater than pressure B i.e. 597 bar (8655 psi) then the required tensioning value as been achieved on this bolt. Repeat this Pressure B check on all the bolts in the flange. If it is found that the "break loose" pressure on any of the bolts is less than pressure B then it is necessary to repeat steps B2.3 to B2.4 to ensure a leak free joint. Final Check. As a final check, use a hammer to "ring" each bolt to ensure that none are slack. On high-pressure, high-temperature applications, it is suggested that the flanges be retightened to the required stress after 24 hours at operating pressures and temperatures to compensate for any relaxation or creep that may have occurred.

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