Bolt Torque & bolt tap test

BOLT TORQUE

ASTM A325 & ASTM A490

HIGH STRENGTH BOLT

TAP CHECK

DERRICK CONSTRUCTION

BEFORE WE GO FURTHER TO UNDERSTAND WHAT IS BOLT TORQUE AND BOLT CHECK,

LETS FIND OUT, WHAT IS BOLT ASTM A325 & ASTM A490 AND DERRICK CONSTRUCTION?

BOLT ASTM A325

ASTM (AMERICAN SOCIETY FOR TESTING AND MATERIALS)

ASTM A325 IS STANDARD FOR HEAVY HEX STRUCTURAL BOLT WHICH HAVE 830 Mpa MINIMUM TENSILE STRENGHT AND HAVE RANGE FROM M12 ~ M36

ASTM A325 IS SIMILAR TO BOLT GRADE 8.8

BOLT ASTM A325 IMPERIAL SYSTEM

ASTM A325

MINIMUM TENSILE STRENGTH = 120/105 KSI

SIZE RANGE = 1/2 1-1/2

METRIC SYSTEM

ASTM A325

MINIMUM TENSILE STRENGTH = 830 Mpa

SIZE RANGE = M12 M36

IMPERIAL SYSTEM = BRITISH

METRIC SYSTEM = AMERICA

BOLT ASTM A490

ASTM (AMERICAN SOCIETY FOR TESTING AND MATERIALS)

ASTM A490 IS A STANDARD FOR HEAVY HEX STRUCTURAL BOLT MADE FROM ALLOY WHICH HAVE 1040 MPA MIN. YIELD STRENGTH AND HAVE RANGE FROM M12 ~ M36


BOLT ASTM A490 IMPERIAL SYSTEM

ASTM A490

MINIMUM TENSILE STRENGTH = 150 173 KSI

SIZE RANGE = 1/2 1-1/2

METRIC SYSTEM

ASTM A490

MINIMUM TENSILE STRENGTH = 1040 Mpa

SIZE RANGE = M12 M36

IMPERIAL SYSTEM = BRITISH

METRIC SYSTEM = AMERICA

DERRICK STRUCTURE What is derrick structure?

A TALL FRAMEWORK ERECTED OVER AN OIL WELL AND USED TO SUPPORT HOISTING EQUIPMENT (FOR RAISING & LOWERING)

BASIC CONCEPT BOLTED STRUCTURE

STRESS AREA = SHARE LOADS

The structure will have slightly movement on its load path and then the bolts will act as stabilizer and to hold the structure.

BASIC CONCEPT BOLTED STRUCTURE

Reference API RP 4G.

Each part of a bolted structure is designed to carry its share of the load. Parts omitted or improperly placed may

contribute to the failure of the structure (5.3.1)

During erection of bolted structures, bolts should be left loose enough, in way of erection, to allow proper fit of adjacent mast/derrick members without distortion and locked in stress (5.3.1)

Reference AISC 13 The snug-tightened condition is the tightness that is attained

with a few impacts of an impact wrench or the full effort of an ironworker using an ordinary spud wrench to bring the connected plies into firm contact (8.1)

CONCLUSION

CONCLUSION 1. DERRICK IS A TALL ERECTED STRUCTURE TO CARRY STATIC LOADS

2. BOLTS ON DERRICK HELP TO MINIMIZE PREMATURE FAILURE (FRACTURE / CRACKS) ON STRUCTURE DUE TO SHARE LOADS (MULTIPLE AXIS FORCE)

3. TENSILE STRENGHT ON BOLTS WILL HELP THE BOLTS TO SUSTAIN THE GIVEN SHARE LOADS

4. THE PRE-TENSION BOLTS SHOULD BE LEFT LOOSE ENOUGH TO ALLOW FIT ADJACEMENT WITHOUT DISTORTION AND LOCKED IN STRESS

5. BOLT GRIP STRENGHT SHOULD FREQUENTLY CHECK OR TORQUE AS PER MANUFACTURE OR SPEC RECOMMENDATION

Definition:

To return the bolt to their original value based on its yield strength by using calibrated wrench

Definition:

To check the in-service bolt by using ordinary spud-wrench and impacts to desired minimum tension

Torque value known

Torque value unknown

BOLT TORQUE TAP CHECK

AISC (American Institute of Steel

Construction)

RCSC (Research Council on Structural

Connection)

ASSEMBLY CONTRACT

DOCUMENT

B. SNUG TIGHTENED JOINT (Prior to the start of work)

A. PRETENSIONED JOINTS (Prior to the start of work)

Turn-of-nut

method (AISC section

9.2.1)

Calibrated

wrench method (AISC section

9.2.2)

Twist-of-type

method (AISC section

9.2.3)

Direct-tension-

indicator (AISC section

9.2.4)

Manufacturer /

Engineer approval (AISC section 2.6.2)

THE BOLTS SHOULD NOT BE

INSPECTED TO DETERMINE THE

ACTUAL INSTALLED PRETENSION (AISC 9.1)

Recommendation reference:

At completion of erection, all bolts should be checked for proper torque. Periodically, all bolts should be checked for proper torque (AP RP 4G, section 5.3.1)

Bolt tensioning shall be achieved using calibrated tensioning methods. Bolts that are specified to be pre-tensioned to a higher value than 50 % of the bolt material minimum ultimate strength shall only be used once (AP RP 4G, section 5.3.1)

The use of the turn-of-nut method is always acceptable for use on bolts which are not to be reused. Reuse of bolts is

acceptable if so specified in the manufacturers instructions or by a professional engineer (AP RP 4G, section 5.3.1)

Check 10% of the bolts at the connections on torque by a calibrated torque wrench. If some bolts are not on the correct pre-stress, then check the complete connection. Put the bolts again to the correct pre-stress by a calibrated torque wrench (NOV Derrick manual No: T7801-Z-MA-001 section 6.3.3)

BOLT TORQUE TAP CHECK Recommendation reference:

For joints that are designated in the contract documents as snug-tightened joints, the bolts shall be installed in accordance with Section 8.1 (Snug-Tightened Joints). For joints that are designated in the contract documents as pre-tensioned or slip-critical, the bolts shall be installed in

accordance with Section 8.2 (Turn-of-nut method, Calibrated wrench method, Twist-of-type method, Direct-tension-indicator) (RCSC section 8)

ASSEMBLY CONTRACT DOCUMENT

B. SNUG TIGHTENED JOINT (Prior to the start of work)

A. PRETENSIONED JOINTS (Prior to the start of work)

Turn-of-nut

method (AISC section 9.2.1)

Calibrated wrench


Twist-of-type


Direct-tension-

indicator (AISC section 9.2.4)

Manufacturer /

Engineer approval (AISC section 2.6.2)

THE BOLTS SHOULD NOT BE INSPECTED TO

DETERMINE THE ACTUAL INSTALLED

PRETENSION (AISC 9.1)

BOLT TORQUE TAP CHECK To return the bolt grip value by using calibrated torque wrench by applying a calculated average torque value to fasteners.

Torque value refer to manufacture recommendation

Manufacture recommendation NO derrick

Size Hot Dip Galvanized Phosphate

M20 8.8 412 Nm 10.

9

465 Nm

M22 8.8 554 Nm 10.

9

626 Nm

M24 8.8 712 Nm 10.

9

804 Nm

M27 8.8 1028 Nm 10.

9

1161 Nm

M30 8.8 1402 Nm 10.

9

1582 Nm

REMEMBER!!



Turn-of-nut is performed by rotating the nut or bolt of a fastener assembly a specific turn angle based on the fastener's length, and diameter while restraining the unturned element from rotating

Table 1 for turn-of-nut pre-tensioning

Bolt length Bolt face normal to bolt axis Tolerance

< 4d 1/3 turn 30 Deg

< 4d > 8d 1/2 turn 30 Deg

< 8d > 12d 2/3 turn 40 Deg

BOLT TORQUE TAP CHECK Match mark:

Match-marking is a drawn line from nut to the extend bolt thread of base metal and this is to improve the ability to inspect bolts that have been pre-tensioned with the calibrated torque wrench method

Match-mark

Before torque After torque

BOLT TAP CHECK

Step 1. Fit the flogger to size nut

Step 2. Apply few impact on flogger until visually the nuts firm (tight) to the surface

Step 2. Spray and draw a match-mark on bolt and nut for next survey

BOLT TORQUE

BOLT TORQUE

Step 1. Check the torque value from derrick drawing & set the torque value on wrench Step 2. Torqueing bolt on derrick. Follow step and manual of torque wrench Step 3. Spray and draw a match-mark on bolt and nut for next survey

THANK YOU REFERENCE - American Institute of Steel Construction (AISC) 13th edition - Research Council on Structural Connections (RCSC) - API RP 4G Operation, Inspection, Maintenance, and Repair of

Drilling and Well Servicing Structures - Derrick NOV manufacturer manual

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QAQC Department [email protected] 2014

Bolt Torque & bolt tap test

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