Keston 50 - GC Installation And Servicing Instructions page 13

WD50/2/1997 Chapter 2 - Boiler Connections
Expansion
Pipe
Boiler
Keston
Strainer
Rad. 2
2.7.2 Sealed Systems
Sealed systems must be designed in accordance with BS 5449 and BS 7074 Pt1.
A typical sealed system is shown in Figure 2.7.2. It must include :
(i) A safety valve fitted on the flow, adjacent to the boiler. It must be non
adjustable and preset to 3 bar. A drain pipe must be attached, at least as
big as the valve connection, and routed to drain in any area not
hazardous nor where it may be subject to freezing.
(ii) An expansion vessel complying with BS 4814 and sized in accordance
with the requirements of BS 5449 and BS 7074 Pt 1. The vessel must be
positioned on the inlet to the pump.
(iii) A filling point, in accordance with local water authority requirements.
(iv) A method of system make-up (automatic or manual), in accordance with
local water authority requirements.
(v) There must be no permanent connection of mains water to the boiler
system.
(vi) The installation must be designed to work with flow temperatures of up to
110
All components of the system including the heat exchanger of the indirect
cylinder must be suitable for a working pressure of 3 bar and a temperature of
o
110 C. Care should be taken in making all connections that the risk of leakage is
minimised.
Installation & Servicing Instructions
Expansion
Tank
22mm pipe
(minimum)
Figure2.7.1 : Open Vented System Diagram
o
C.
Page : 10
The Keston 50, 60 & 80 Condensing Boilers
Minimum
8ft Height
Pump
By-pass
Bal.
Valve
Rad. 1
3 Way Cylinder
Valve
L/S