Double Pipe Sub-Gravity Feed System; Single Pipe Suction Lift With De-Aerator; Pipework; Boiler Isolation Valve - Bosch WORCESTER Greenstar Heatslave II 12/18 Installation, Commissioning And Servicing Instruction Manual

Pre-Installation
4.3.2

Double pipe sub-gravity feed system:

Maximum suction height 3.5 m. Non-return valves must be fitted to the
inlet and return oil line between the oil pump [9] and oil storage tank [1].
1
11
150mm
2 3 4
Fig. 5 Double pipe feed
Maximum pipe run for double pipe sub-gravity fed system
Head (m) 10mmØ 12mmØ
0 50 100
0.5 44 100
1.0 38 95
1.5 32 80
4.3.3

Single pipe suction lift with de-aerator:

Maximum suction height 3.5 metres. The oil tank [1] must be positioned
below the oil pump [9]. Create an inlet and return loop between the de-
aerator [12] and oil pump [9].
A non-return valve must be incorporated within the de-aerator or fitted
to the oil line between the oil storage tank [1] and the de-aerator [12].
A top feed oil tank fitted with a de-aerator using an internal non-return
valve should have any non-return valves fitted in the base of the tank to
the suction line removed to assist purging air from the oil line.
1
2 3 4
Fig. 6 De-aerator feed
Maximum pipe run for single pipe suction lift with de-aerator
2.5kg/h 5kg/h
Head (m) 8mmØ 8mmØ
0 100
0.5 95
1.0 80
1.5 70
2.0 60
2.5 45
3.0 35
3.5 25
The table and illustration above is a guide only and does
not in any way override the de-aerator manufacturer's
instructions
12
6 8
14
5
9 10
3 7 14 13
6720813284-09.2Wo
Head (m) 10mmØ 12mmØ
2.0 26 66
2.5 20 50
3.0 14 37
3.5 8 22
12 6 8
14
9 10
5
3 7 14 13
FUEL FLOW RATE
10kg/h 10kg/h
8mmØ 10mmØ
55 26 100
45 23 100
40 20 90
35 17 75
30 14 65
25 11 50
15 8 35
10 5 20
4.3.4

Pipework

▶ Refer to the oil supply sections Single pipe gravity feed
system: 4.3.1, Double pipe sub-gravity feed system: 4.3.2 & Single
pipe suction lift with de-aerator: 4.3.3 for oil supply pipework
configurations.
Oil supply pipework considerations:
• Lay the oil supply pipe as straight and level as possible to avoid air
pockets and unnecessary friction losses.
– Route away from the boiler access door or other hot surfaces.
• Install a manual isolating valve to the oil supply pipe, as close to the
oil storage tank as possible.
• Fit an oil strainer and water separator to the oil supply pipe, near the
oil storage tank.
– Fit an additional oil filter (70 μm max filtration size) close to the
boiler, but not inside the boiler casing.
• Fit a fire valve in accordance with BS 5410.
– The fire valve should be fitted externally to the building with the
fire valve sensor located within the appliance case.
– A fire valve with a shut off temperature of 85°C or higher must be
fitted to avoid the possibility of nuisance shut offs.
– A capillary type valve provides a neat and simple installation.
Alternatively, a fusible link or electrical system may be used.
• Under no circumstances should a combination isolating/fire valve be
used as the sole fire protection device.
4.3.5

Boiler isolation valve

▶ Use copper pipe of the correct diameter according to the information
shown in oil supply sections 4.3.1, 4.3.2 & 4.3.3.
– If using soft copper pipe (R220) with a compression fitting, an
insert must be used to prevent the pipe from collapsing or
distorting when the fitting is tightened.
▶ Slide nut [1] and olive [5] onto the oil supply pipe [4].
▶ Slide insert [3] into the pipe.
▶ Offer the pipe to the fitting [2] and tighten the nut [1].
1
5
4
3
Fig. 7 Isolation valve bracket removed for clarity
▶ Use flexible hoses to connect to the oil pump.
Greenstar Heatslave II
2
2022 + 6 721 843 978 (2022/01)