Pipe End Preparation
Guidance on preparing pipe ends for KLAMFLEX couplings, following SABS 719 and BS 534 standards, with emphasis on sealing surface quality and assembly clearance.
Pipe End Preparation
Guidance on preparing pipe ends for KLAMFLEX couplings, following SABS 719 and BS 534 standards, with emphasis on sealing surface quality and assembly clearance.
Prepare pipe ends to ensure satisfactory sealing and coupling assembly
Proper pipe end preparation is essential to ensure effective sealing and reliable coupling assembly.
Surface Preparation
By its very nature, the KLAMFLEX coupling system relies upon surface contact of the sealing rings, and consideration must be given to pipe end preparation on pipes with naturally rough or uneven surface finish.
Where surface dressing is required to remove weld bedding, care must be taken not to overdress the pipe end, causing pitting or flat spots.
In general, the recommendations of SABS 719-1971 and BS 534-1990 Section 15 ensure a satisfactory surface finish.
Pipe End Clearance (Dimension ‘L’)
Dimension ‘L’ is the length from the ends of the pipes which must be rounded where necessary to meet the tolerance required. It is also the amount of “Clearance” to permit coupling assembly, and applies equally for coupling sleeves with centre register, without centre register or with locating plug.
For distance ‘L’, the pipe must be free from any peaks, flats, depressions, roll marks, weld beads or any other such defects likely to affect the seal.
See Figure 4 below.
Coupling Installation (Dimension ‘M’)
Where it is necessary to slide the coupling completely onto one pipe end, the wrapping must be cut back on site for minimum distance “M”.
Closing Connections
For closing connections, only coupling sleeves without register or with locating plugs may be used.
See Figure 5 below.
Figure 4 — Pipe end preparation
Dimension ‘L’
Figure 5 — Closing connection
arrangement
Table 1
| DN (mm) | Sleeve Length (mm) | Distance L for Normal Coupling Assembly (mm) |
Distance M for Closing Connections (mm) |
|---|---|---|---|
| ≤ 326 | 102 | 100 | 152 |
| > 326 - ≤ 1150 | 178 | 150 | 254 |
| > 1200 | 356 | 300 | 500 |