Pipe Fittings Manufacturer for Worldwide Distribution

Fitting Instructions Above 300mm


KLAMFLEX Unassembled Couplings are supplied for sizes above 326mm pipe OD. As the name suggests the couplings are supplied with sleeves, flanges, sealing rings and bolts unassembled. Fitting of KLAMFLEX Unfitted shall be conducted according to the following procedure.

  1. Ensure the pipe ends are correctly prepared. All with which the gaskets come into contact are to be thoroughly cleaned immediately before coupling installation, thus allowing the gaskets to seal effectively. A distance of one centre sleeve length plus 50mm on each pipe end should be prepared to remove all loose rust, dirt and foreign matter. It is important that the pipe ends be smooth, concentric and within specified tolerances (SABS 719-1971 section 5, BS 534-1990 section 14). It is important that weld beads are ground flush maintaining correct surface profile
  2. Reference marks should be placed on the pipes to facilitate in centering the Coupling Sleeve over the gap between the pipes in accordance to KLAMFLEX setting gaps for each specific Coupling
  3. Larger-diameter pipe and Couplings may become out of round in transportation and handling. Therefore it is normal to expect to use jacks, wedges, shims or other means to facilitate assembly of the Coupling on the pipe ends
  4. The end rings shall be placed on the pipes
  5. A suitable gasket lubricant (such as soapy water) must be applied to the pipe ends and the sealing rings, care must be taken to ensure the gaskets are clean. The gaskets shall then be placed on the pipe ends with bevelled faces toward the centre sleeve
  6. The centre sleeve shall be placed on one pipe end
  7. The pipe ends shall be aligned leaving the appropriate gap tabulated in Setting Gaps. Adjustment of the trench bed may be necessary. Where locating plugs are used, the setting gap should be increased by 9.5mm for sizes up to 326mm OD and 12.5mm for sizes above 326mm OD to avoid contact with the plugs
  8. The centre sleeve shall then be moved into position, centred over the gap with reference to the marks made on the pipe ensuring the Coupling is central over the gap
  9. When the centre sleeve is properly placed, with the gap between the OD of the pipe and the ID of the centre sleeve distributed evenly the gaskets shall be moved into position with bevelled faces of the gaskets against the centre sleeve end. End-rings shall be moved into place behind the gaskets
  10. Bolts shall be installed in the end-rings holes and tightened to the KLAMFLEX recommended torque. To assure correct end-ring seating and gasket compression, the bolts must be tightened in pairs at diametrically opposite positions in a circular sequence. Bolt up evenly giving nuts one or two turns at a time to the prescribed torque rating of 80 - 120Nm (M16 bolt)
  11. The tightening sequence assures that the end-rings are pulled evenly to compress the gaskets uniformly and to maintain appropriate gap. The tightening of the bolts shall be repeated as many times as necessary to bring all fasteners to the equired torque rating, so as to provide a leakproof installation at the specified test pressure. If an effective sealing is not attained at the recommended torque, the Coupling shall be loosened, realigned and the bolts retorqued
  12. Torque ratings for GRP pipes are to be decided on after consultation with the specific GRP pipe supplier, as each supplier develops pipe with its own specific glass filament configuration.

Note: These specifications relate to product operating at 16 bar working pressure. Contact KLAMFLEX for torque specifications at different working pressures.