A variety of anchoring techniques
The anchoring of ductile iron pipelines can be achieved using two technical solutions :
- Insert type anchoring techniques
- Bead type anchoring techniques
Insert type anchoring techniques
With insert type anchoring systems, joint separation is prevented by means of hard stainless steel inserts which fit into sockets in the pipes or fittings. These inserts have teeth which grip the spigot end of the pipe or fitting and lock it against axial displacement. These insert systems rely on the ductile nature of the cast iron which allows the penetration of inserts without any risk of failure.
The main advantage of these systems is that they can be implemented on site without any special preparation.
The inserts can be fitted in the sealing chamber, as in the case of anchoring devices of the STANDARD Vi type, or in a specially designed anchoring chamber, as in the case of the UNIVERSAL Vi anchoring system.
Bead type anchoring techniques
With bead type anchoring systems, joint separation is prevented by pressing a metal locking ring, which fits into socket in the pipe or into the mating flange installed before the socket, onto a metal bead on the spigot end. This bead is made by welding (in the case of pipes) or by casting during manufacture (which is generally the case for fittings).
The main advantage of these anchoring systems is their ability to withstand very high pressure.
With bead type devices, the anchoring mechanism is always located in a specially dedicated chamber.
Main advantages of the two anchoring techniques
Insert type anchoring
- Quick and easy to install
- Medium or high pressures
- Easy cutting on site
- Competitive costs
Bead type anchoring
- Very high pressures
- Constant operation with alternating stresses
- Can be used for pulling pipes
- Extreme service conditions