IDEAL INDUSTRIES HE9, HE18, HE12, HE15 manual Sealed System Requirements

GENERAL

6 SEALED SYSTEM REQUIREMENTS - continued

7.Mains Connection

There must be no direct connection to the mains water supply or to the water storage tank supplying domestic water, even through a non-return valve, without the approval of the local water authority.

8.Filling

The system may be filled by one of the following methods:

a. Through a cistern, used for no other purposes, via a ball valve permanently connected directly to a service pipe and / or a cold water distributing pipe.

The static head available from the cistern should be adequate to provide the desired initial system design pressure. The cold feed pipe from the cistern should include a non-return valve and a stop valve with an automatic air vent connected between them, the stop valve being located between the system and the automatic air vent. The stop valve may remain open during normal operation of the system if automatic water make-up is required.

b. Through a self-contained unit comprising a cistern, pressure booster pump (if required) and, if necessary, an automatic pressure reducing valve and flow restrictor. The cistern should be supplied through a temporary connection from a service pipe or cold water distributing pipe.

This unit may remain permanently connected to the heating system to provide limited automatic water make-up. Where the temporary connection is supplied from a service pipe or distributing pipe which also supplies other draw-off points at a lower level then a double check valve shall be installed upstream of the draw-off point.

c. Through a temporary hose connection from a draw-off tap supplied from a service pipe under mains pressure. Where the mains pressure is excessive a pressure-reducing valve shall be used to facilitate filling.

The following fittings shall form a permanent part of the system and shall be fitted in the order stated:

A stop valve complying with the requirements of BS. 1010, Part 2 (the hose from the draw-off tap shall be connected to this fitting).

A test cock.

A double check valve of an approved type.

•Thoroughly flush out the whole of the system with cold water, without the pump in position.

•With the pump fitted, fill and vent the system until the pressure gauge registers 1.5 bar (21.5lb/in2).

Examine for leaks.

•Check the operation of the safety valve by manually raising the water pressure until the valve lifts. This should occur within ± 0.3 bar (± 4.3lb/in2.) of the pre-set lift pressure.

•Release water from the system until the initial system design pressure is reached.

•Light the boiler and heat the system to the maximum working temperature. Examine for leaks.

•Turn off the boiler and drain the system while still hot.

•Refill and vent the system.

Sizing procedure for expansion vessels: The volume of the expansion vessel (litres) fitted to a sealed system shall not be less than that given by Table 6, multiplied by a factor of 0.8 (for flow temperatures of less than 88 oC).

Table 6

Safety valve setting		3.0 bar			2.5 bar		2.0 bar
Vessel charge and initial	0.5	1.0	1.5	0.5	1.0	1.5	0.5	1.0
system pressure	bar	bar	bar	bar	bar	bar	bar	bar
Total water content of system				Expansion vessel volume
(litres)					(litres)
25	2.1	2.7	3.9	2.3	3.3	5.9	2.8	5.0
50	4.2	5.4	7.8	4.7	6.7	11.8	5.6	10.0
75	6.3	8.2	11.7	7.0	10.0	17.7	8.4	15.0
100	8.3	10.9	15.6	9.4	13.4	23.7	11.3	20.0
125	10.4	13.6	19.5	11.7	16.7	29.6	14.1	25.0
150	12.5	16.3	23.4	14.1	20.1	35.5	16.9	30.0
175	14.6	19.1	27.3	16.4	23.4	41.4	19.7	35.0
200	16.7	21.8	31.2	18.8	26.8	47.4	22.6	40.0
225	18.7	24.5	35.1	21.1	30.1	53.3	25.4	45.0
250	20.8	27.2	39.0	23.5	33.5	59.2	28.2	50.0
275	22.9	30.0	42.9	25.8	36.8	65.1	31.0	55.0
300	25.0	32.7	46.8	28.2	40.2	71.1	33.9	60.0
Multiplying factors for
other system volumes	0.0833	0.109	0.156	0.094	0.134	0.237	0.113	0.20

12 classic HE - Installation & Servicing