Modular valve systems necessitate the use of a flexible pipe that can be laid in single lengths between the modules and terminals. It is not recommended that rigid pipes are used to connect between modules and terminals.
To handle the temperatures and pressures in heating and chilled water systems in commercial buildings comfortably, pre-insulated flexible multi-layer pipe should be the main choice. Figure 3 shows the typical construction of a multi-layer pipe. The diagram below shows the structure of the Aluflex pipes:
The multi-layer pipe consists of 3 layers. An internal butt welded aluminium pipe is sandwiched between two layers of PE-RT (polyethylene of raised temperature resistance).
The aluminium layer brings many benefits relative to plastic pipes:
- Higher strength
- More temperature resistant
- Less expansion
- Zero oxygen diffusion
- No sagging
On complex commercial projects it is essential that pipe fittings and their connections are 100% secure to avoid the risk of leaks when the system is pressurised.
SAV multi-layer flexible pipe can be supplied with a crimped jointing system. The crimped jointing system has the following safety features:
- Two inspection holes ensure that the flexible pipe has been fully inserted and is flat up against the fitting.
- Two O-rings are used to seal against the multi-layer pipe. Flat O-rings are used since they have less chance of catching on the edge of the flexible pipe and being dislodged or damaged.
All fittings are tested during manufacture. The diagrams below show the typical crimped jointing system components.
Pipes and valves must be properly insulated to prevent heat losses from heating circuits and condensation in chilled water circuits. If insulation and a vapour seal aren’t properly applied on chilled water pipes, condensate will form and water damage may occur.
Insulating rigid pipes can be expensive due to the need to cut and fit multiple lengths of rigid insulation between elbows and tees. Valves and other pipeline components can also be difficult to insulate. Any solution adopted for valves has to be flexible enough to permit regular access during the pre-commission cleaning and commissioning activities.
Modular flexible pipe solutions greatly simplify the process. Flexible multi-layer pipes can be supplied pre-insulated (to BS476 Class 0 fire rating) thereby avoiding the need for on-site application of insulation. The modules themselves are supplied pre-insulated i.e. in a box with an internal layer of insulating foam. The boxes are sealed to prevent vapour ingress.