Raypak B0200 Owner's Manual page 18

CONNECTIONS – PLUMBING
The table below provides indicative pipe and pump sizes for typical installations
Model Pump
UPS
Series
200 20-60B
280 20-60B
350 32-80B
430 32-80B
PUMP SELECTION
In order to obtain the best possible water flow in the system a correctly sized pump must be installed. Refer to the
Flow Rate and Pressure Drop table below and allow for the system head pressure when sizing the pump.
The pump selected should provide a 10 to 20°C temperature difference between the water heater inlet and outlet
when the water heater is at full fire.
Mechanical heating systems with multiple zones may require additional pump(s) refer to
page 24.
Model
200
280
350
430
PRESSURE RELIEF VALVE
The pressure relief valve and elbow are shipped in a plastic bag inside the water
heater. The pressure relief valve must be fitted before the water heater is operated.
Fit the elbow supplied in the plastic bag to the ¾" connection on the inlet/outlet
header then screw the relief valve onto the other end of the elbow.
Seal the treads using Teflon tape, never hemp. A drain line must be
installed in accordance with AS/NZS 3500.4 to carry the discharge
from the valve to a suitable discharge point.
On/Off Models
Modulating Models
When the water heater is connected to a storage cylinder for water heating
applications, a correctly sized and pressure rated TPR valve MUST be fitted to the storage cylinder.
NOTE: Where a modulating water heater is used in a water heating application it will be necessary to replace the
310 kPa relief valve provided with the water heater with one rated at 850 kPa.
RELIEF VALVE DRAIN
A copper drain line must be fitted to the relief valve to carry the discharge clear of the water heater. Connect the
drain line to the relief valve using a disconnection union. The pipe work from the relief valve to the drain should be
as short as possible and fall all the way from the water heater with no restrictions. It should have no more than
three right angle bends in it. Use DN20 pipe.
The outlet of the drain line must be in such a position that flow out of the pipe can be easily seen (refer to
AS/NZS 3500.4) - but arranged so hot water discharge will not cause injury, damage or nuisance. The drain line
must discharge at an outlet or air break not more than 9 metres from the relief valve.
Branch Size
Speed inches
3 1
3 1¼
2 1¼
3 1¼
WATER FLOW RATE AND PRESSURE DROP
10°C Rise
l/sec kPa
1.04 3
1.47 8
1.82 13
2.24 17
Relief Valve Pressure Rating
850 kPa (125 psi)
310 kPa (45 psi)
Minimum Manifold Header
1
mm
Unit
25 25
32 32
32 32
32 32
15°C Rise
l/sec kPa
0.69 3
0.98 4
1.22 6
1.49 8
Pressure
Relief Valve
18
Size Required (mm)
2 3
Units Units
32 40
32 50
40 50
40 50
„Multi Pump Options‟
20°C Rise
l/sec
0.52
0.74
0.91
1.12
4
Units
50
50
50
65
on
kPa
3
3
3
4