Torque Wrench
CATEGORY : Services

Gas cylinders — Fitting of valves to Steel gas Cylinders  Preparation  Each valve and cylinder thread shall be examined and free from ragged edges, burrs, paint ore sealants

 Valving procedure for taper threaded valves  Wrapping with sealant tape  Wrapping of the valve stem with tape shall commence at the small end of the taper; the sealant tape, shall be wound clockwise when looking from the base of the valve.  Wrapping shall be such that it is by a maximum of 3 mm and a minimum of 1 mm.  Tape shall then be overlapped during wrapping to give an even double thickness all the way up to include the top thread of the valve stem.  Excessive tape thickness may increase the stress or push the tape out.  Valve Torqueing  After the valve has been screwed in by hand as far as possible and after making sure that sufficient threads are engaged, a properly fitting tool shall be used to tighten the valve into the cylinder.  For threads according to ISO 11363-1, the torque applied shall be as specified in table below.  The minimum value obtained to move the valve shall be within the limits of table below and properly calibrated torque wrench shall be used.  Setting the Torque Wrench  Check to ensure torque wrench is Calibrated and with the dates.  Pull bottom out to show Green strip  Rotate clockwise to increase Nm and anti-clockwise to decrease the Nm  Set Torque Wrench 150Nm for Steel Cylinders  Set Torque Wrench to 90Nm for Aluminium Cylinders  Push bottom back and ensure no green is showing  Tightening the Valve  Once you have set the torque wrench, fit the correct size shifting spanner to the valve  Rotate the Torque wrench in the direction of the arrow to tighten the valve  Once the Torque wrench clicks stop tightening the valve as this means that the valve has been torqued correctly