Technical brochure Smart 841 KB

SLE130-160 SLE+210-240-300
ADDITIONAL INSTALLATION INSTRUCTION FOR UK KITS.
IMPORTANT!
DO NOT UNDER ANY CIRCUMSTANCES SWITCH ON THE
IMMERSION HEATER BEFORE THE PRIMARY TANK IS FILLED.
SLE+040113
CUSTOMER/TECHNICAL ASSISTANCE & ORDER INFORMATION
Telephone: 01383 820 100
Fax: 01383 820 180
e-mail: uk.info@acv.com
web address: www.acv.com
ACV UK Ltd.
St. Davids Business Park
Dalgety Bay
Fife
KY11 9PF
Scotland
Further copies of instructions can be downloaded at: www.acv.com
Manufactured at:
ACV International
Kerkplein 39
B – 1601 Ruisbroek
Belgium
Telephone: 0032 237 81235
e-mail: international.info@acv.com
web address: www.acv.com
Members of:
For further information on the HWA Charter Membership, please
refer to the HWA website: hotwater.org.uk
INDEX
INTRODUCTION
1
Intended users of these instructions
Warnings
1
1
1. Operation
2
2. Construction
3
3. Installation
Domestic
Wiring the thermostats
Primary
Immersion Heater
4
5
5
6
4. System Schematics
Typical un-vented
Typical open vented
Proposed SLE+ diverted primary
Proposed SLE+ radiators and UFH
Typical ‘S-Plan’ electrical
Typical ‘Y-Plan’ electrical
7
7
8
8
9
10
5. Commissioning
11
6. Performance
11
7. Maintenance
12
8. Parts List
12
9. Technical Data
SLE 130 - 160
SLE+ 210 - 240 - 300
13
14
10. Discharge Pipe
Extract of ‘Building reg. G3’
15
18
T E C H N I C A L
A N D
I N S T A L L A T I O N
INTRODUCTION
Intended users of these instructions:
- The specifying engineer.
- The installation engineer.
- The owner or user.
- The service engineer.
Warnings.
THE INSTALLER MUST READ AND UNDERSTAND THIS MANUAL BEFORE FITTING THIS
APPLIANCE.
IMPORTANT: Do not under any circumstances switch on the immersion heater before the
primary tank is filled.
Serious damage may result to the heater in addition to danger of personal injury and damage
to property if the heater is switched on when dry.
IMPORTANT: Always isolate electrical supplies and if necessary the water supply before
working on the unit.
IMPORTANT: Always fill and pressurise the secondary (domestic) tank first, filling and
pressurising the primary (heating) tank may result in crushing damage to the domestic tank.
IMPORTANT: ACV recommends the use of a corrosion inhibitor in the primary (heating)
system. The warranty will be invalidated if upon inspection it is found that a tank has failed
due to corrosion caused by the lack of an inhibitor.
IMPORTANT: Ensure that the air is purged from the primary jacket using the air vent on the top
centre of the cylinder.
These instructions form an integral part of the equipment to which they refer and the user must
be provided with a copy.
The product must be installed and serviced by qualified engineers, in compliance with current
standards.
ACV cannot accept liability for any damage resulting from incorrect installation or from the use of
components or fittings not specified by ACV.
Any failure to follow the instructions regarding tests and test procedures may result in personal
injury.
ACV reserves the right to change the technical specifications and components of its products
without prior notice.
1
T E C H N I C A L
A N D
I N S T A L L A T I O N
1. OPERATION
A = Stainless steel internal tank
B = STW 22 carbon steel exterior tank
C = High density polyurethane foam insulation
D = Heating fluid entry point
E = Heating fluid outlet point
F = Sanitary hot water outlet
G = T & P relief valve connection
H = Cold water inlet
I = Control thermostat
K = Control thermostat pocket
L = Primary air vent
M = Co-polymer polypropylene top cover
N = Co-polymer polypropylene jacket
Principle:
ACV Tanks (tank in tank) comprise of two concentric water cylinders. Tank (A) is manufactured in solid
stainless steel and contains the domestic water for use at the sanitary hot water outlets. The exterior tank
(B) is manufactured from STW 22 carbon steel, this tank holds the primary heating fluid which is circulated
from the boiler, as the primary fluid passes between the two tanks the heat is transferred to the domestic
water.
Operation:
When the thermostat (I) calls for heat the primary pump is activated (or motorised valve is opened) and
primary fluid is circulated in the outer tank and transfers its heat to the domestic water. Once the
thermostat set temperature is achieved it will open and deactivate the primary pump (or close the
motorised valve). Initial heating from cold will take between 10 and 20 minutes (depending on tank size
and boiler output) – when operating temperature is achieved the recovery becomes faster.
Operational Cycle:
2
T E C H N I C A L
2.
A N D
I N S T A L L A T I O N
CONSTRUCTION
Internal tank:
This tank is the heart of the assembly; it has to withstand the corrosive nature of mains water and the
temperature variations of stored water whilst working at high pressures. It is manufactured from solid
stainless steel and welded in an inert Argon atmosphere (Argon Arc). Before being assembled the tank
material is subjected to a rigorous cleaning and passivation process to increase its resistance to
corrosion. The inner tank is also corrugated which allows it to freely expand and contract with temperature
and pressure variations, shrugging off any lime scale deposits. Due to this, the tank does not require an
inspection cover to facilitate the removal of lime.
Insulation:
High density injected polyurethane foam – 50mm thick. Containing no CFC’s, having a GWP =
0.00025 and ODP = 0
Jacket:
The tank is covered in a co-polymer polypropylene jacket, this is a plastic material that offers a high
resistance to impact and is also aesthetically pleasing.
Controls:
The tanks come complete with a control and high limit thermostat built into the top cover of the jacket.
Thermostat control:
The control is graduated from 1 to 5, 1 is minimum = 60°C and 5 is maximum = 85°C.
In the case of a prolonged absence precautions must be taken to ensure there is no risk of freezing. The
tank is delivered with the thermostat pre-set to a minimum of 65°C to eliminate the risk of legionella
bacteria forming and complies with the recommendations of the World Health Organisation. The
thermostat control dial can be removed to allow lower temperature settings, see sketch and description
below.
Modifying the IMIT thermostat:
1. Remove the control dial.
2. Take out the metal spring stop.
3. Replace the control dial.
3
T E C H N I C A L
3.
A N D
I N S T A L L A T I O N
INSTALLATION (130 to 300 Smart Paks)
Domestic:
Parts List.
Installation
Option 1.
1. Pressure control valve 3.5bar.
2. Expansion vessel 3.5bar.
3. Check/Expansion valve assembly 6bar.
4. Thermostatic mixing valve.
5. Temperature & pressure relief valve 7bar.
6. Tundish.
7. 22mm Myson MPE222 spring return zone valve.
8. Pipe work kit includes:
1 in No. 22mm equal tee.
1 in No. 22mm elbow.
2 in No. 22mm x 1" FI BSP Adaptors.
5 lengths 22mm Copper tube (A to C on drawing).
Note: Secondary return pipework and fittings are not included in
the kit.
Guidance for Installation.
1. Connect 22mm x 1" FI BSP adaptors to cold water inlet (blue) and hot
water outlet (red) connections on tank.
installed correctly, cold/hot inlet ports are marked on body, i.e. hot to H cold
to C outlet to MIX.
Note:- discharge pipework to tundish is not supplied.
3. Orientate mixing valve hot water outlet to desired position and tighten.
4. Connect Check/Expansion valve to cold water inlet pipe (A) and orientate
Expansion vessel connection to suit installation.
5. Connect Pressure Reducing Valve to Check/Expansion valve (a light
smear of jointing compound to PTFE ring will ease assembly) and orientate
to ensure balanced cold water take-off faces either front or rear (blank
supplied if take-off is not to be used).
6. Remove 3/4" black plastic plug from Check/Expansion valve and fit
Expansion Vessel (seal with PTFE tape).
7. Connect Temperature and Pressure relief valve to 1/2" connection and
orientate into position. Do not run drain discharge pipework across top of
tank.
8. Connect both Temperature and Pressure relief valve/Expansion valve
discharge pipework across top of tank.
9. Install Tundish outlet pipework as per Building regulation G3 (for further
guidance refer to controls installation and maintenance instructions).
Flush pipework and commission.
4
T E C H N I C A L
A N D
I N S T A L L A T I O N
Wiring the thermostat:
To comply with ‘The Building Regulation 1991 G3.6’ the manual reset high limit thermostat must be wired to a
self-closing motorised valve or some other suitable device to shut off the primary flow to the cylinder.
The thermostatic controller should be used to regulate the temperature of the tank by controlling the heating
pump or zone valve supplying the unit (note that a spring return valve must be connected to the high limit stat
for normal operation, i.e. the valve will be energised to open by the thermostat and then spring closed when the
circuit is broken). The switch wire from the pump or valve can be wired to the tank controls via the 6 pin plug.
See diagram below.
Thermostat wiring schematic.
High Limit Stat
Thermostat
Factory Wired
Installer Wired
Please note N is a switched LIVE not NEUTRAL.
(Typical ‘S & Y-plan’ wiring schematics are on pages 12 &13).
ACV recommends that the cylinder is electrically cross bonded to earth.
Primary system connections:
The primary flow and return connections to the tank should be made using the appropriate sized fittings with a
male BSP component that will allow the disconnection and removal of the unit. A self-closing motorised valve or
some other suitable device must be fitted to shut off the primary flow to the cylinder. Care must be taken to
ensure that the connections are watertight to avoid any leakage that may go undetected and cause external
corrosion damage to the tank.
Distribution Pressure
The mains water supply must be fed to the unit via the supplied mains kit, this will maintain a maximum
distribution pressure of 3.5 Bar.
Purging
After filling and before using it will be necessary to purge air from both the primary (heating) and
secondary (domestic) tanks. The domestic can be purged by opening a hot outlet at the highest point (or
by venting the temperature and pressure relief valve), the primary (heating) tank can be vented using the
air vent located on the top of the tank (ensure vent is tightened after use).
5
T E C H N I C A L
A N D
I N S T A L L A T I O N
Immersion Heater
The SmartLineE range of tanks have the facility for fitting a 3kW immersion heater for back-up emergency use
when the primary heating fails not as a permanent form of summer time heating, this heater must be wired to
its own 13 Amp fused spur and as described in the installation instructions for Thermco immersion heaters.
Installation Instructions for Thermco Immersion Heaters.
Contact details: www.thermco.com - enquiries@thermco.com - 01502 576800
1. Ensure mains voltage corresponds to the voltage rating of the heater as shown on the rating label
on the terminal cover.
2. Install the heater into the water tank, using the gasket or ‘O’ ring supplied (the use of sealing
compounds is not recommended). Use a shaped spanner to tighten (stillsons should not be used).
3. It is essential that water fully covers the heating element to a depth of at least 100mm. Under no
circumstances must the heater be permitted to run dry – serious damage may result to the heater
in addition to danger of personal injury and damage to property.
4. Check for possible leakage before wiring.
5. Wire the heater in accordance with the diagram below. The heater should be wired through a
double pole isolating switch or controller, having contact separation of at least 3mm using
1.5sqmm flexible cable, 85°C rubber insulated HOFR sheathed, complying with BS6141 Table 8. It
must be fully earthed. Ensure all terminals are securely made, however do not use excessive force
when tightening.
6. In the event of the manually resettable cut out operating, isolate the heater from the mains,
investigate and identify the cause of cut out, rectify before resetting and then re-energise the
heater. Replace the terminal cover securely before re-energizing.
7. If problems continue replace the thermostat(s).
8. All heaters conform to EEC directive 76/889 for radio interference and comply with BS 800:1977.
BEAB
APPROVED
Heater Series
A*D, B*D, C*D, D*D
(*may be either A,E or F)
Heater Series
A*S, B*S, C*S, D*S
(*may be either A,E or F)
WARNING!
UNDER NO CIRCUMSTANCES CAN THE IMMERSION HEATER BE SWITCHED ON BEFORE THE
PRIMARY TANK IS FILLED. SERIOUS DAMAGE MAY RESULT TO THE HEATER IN ADDITION TO
DANGER OF PERSONAL INJURY AND DAMAGE TO PROPERTY IF HEATER IS SWITCHED ON WHEN
DRY.
4.
SYSTEM SCHEMATICS
Typical un-vented application
6
T E C H N I C A L
A N D
I N S T A L L A T I O N
Typical open vented application
Proposed SLE+ schematics.
7
T E C H N I C A L
A N D
I N S T A L L A T I O N
SLE+ Diverted Primary Flow
At high DHW demand or DHW charging Heat Pump
can operate at elevated temperature (45-55°C) and
flow is diverted to top inlet. During normal operation
for UFH (30-40°C) flow is to lower connection.
SLE+ Radiators and Under floor
Typical ‘S-Plan’ schematic.
8
T E C H N I C A L
A N D
I N S T A L L A T I O N
CONTROL TERMINAL NUMBERING MAY
DIFFER FROM THOSE SHOWN. ALWAYS
REFER TO THE INSTRUCTIONS SUPPLIED
WITH YOUR CONTROL PACKAGE.
EARTH CONNECTION IS NOT REQUIRED
WITH MYSON ZONE VALVE, FITTING
INSTRUCTIONS INCLUDED WITH VALVE.
ACV 6 PIN SOCKET
FACTORY WIRED
N IS SWITCHED LIVE
NOT NEUTRAL
Typical ‘Y-Plan’ schematic.
9
THIS DIAGRAM IS FOR GUIDANCE ONLY.
ACV ACCEPT NO LIABILITY FOR DAMAGE
TO EQUIPMENT ARISING FROM ERRORS
OR OMISSIONS INADVERTENTLY
CONTAINED WITHIN THIS DIAGRAM.
T E C H N I C A L
A N D
I N S T A L L A T I O N
CONTROL TERMINAL NUMBERING MAY
DIFFER FROM THOSE SHOWN. ALWAYS
WITH YOUR CONTROL PACKAGE.
EARTH CONNECTION IS NOT REQUIRED
WITH MYSON ZONE VALVE, FITTING
INSTRUCTIONS INCLUDED WITH VALVE.
ACV 6 PIN SOCKET
FACTORY WIRED
N IS SWITCHED LIVE
NOT NEUTRAL
5.
COMMISSIONING
10
THIS DIAGRAM IS FOR GUIDANCE ONLY.
ACV ACCEPT NO LIABILITY FOR DAMAGE
TO EQUIPMENT ARISING FROM ERRORS
OR OMISSIONS INADVERTENTLY
CONTAINED WITHIN THIS DIAGRAM.
T E C H N I C A L
A N D
I N S T A L L A T I O N
Characteristics:
Maximum water supply pressure to the reducing valve
Operating pressure
Expansion vessel charge pressure
Expansion valve setting
Maximum primary working pressure
Temperature & pressure relief valve pressure setting
Temperature & pressure relief valve temperature setting
16 Bar
3.5 Bar
3.5 Bar
6 Bar
3 Bar
7 Bar
92-95 °C
1. Flush the tank with fresh mains water then fill, vent and pressurise domestic water circuit as
previously described.
IMPORTANT: Always fill and pressurise the secondary (domestic) tank first, filling and
pressurising the primary (heating) tank may result in crushing damage to the domestic tank.
2. Fill the primary circuit taking care not to exceed 2 Bar.
3. Purge the air from the primary tank.
4. Switch on and operate.
IMPORTANT NOTE:
ACV recommends the use of a corrosion inhibitor in the primary (heating) system. The warranty
will be invalidated if upon inspection it is found that a tank has failed due to corrosion caused
by the lack of an inhibitor.
6.
PERFORMANCE
Performances
Type
Peak output
(l/10min)
SLE 130
40°
C
236
45°
C
202
60°
C
117
SLE 160
321
275
161
406
348
209
547
469
272
800
600
370
SLE+21
0
SLE+24
0
SLE+30
0
Operating conditions:
1st hour output
(ltrs/60min)
Continuous output
(ltrs/hr)
Maximu
m Boiler
Output
(kW)*
Primar
y flow
rate
(ltrs/hr
)
Heat
up
time
10°C
–
85°C
(min)
Heat up
time
15°C–
60°C
(min)
3kW
immrsn*
*
Heat up
time
15°C–
60°C
(min)
6kW
immrsn*
*
23
2100
22
136
68
40°C
45°C
60°C
40°C
45°C
784
106
3
134
9
182
0
236
0
672
384
658
564
60°
C
320
911
549
890
763
465
31
2600
22
169
84
970
576
39
3500
20
213
106
769
53
4200
20
254
127
970
68
5500
22
307
154
115
6
156
0
198
8
689
913
110
0
primary fluid
cold inlet
113
2
152
7
210
0
130
9
166
5
85°C
10°C
*Maximum boiler input. Should a lower capacity boiler be used the performance will be reduced.
11
T E C H N I C A L
A N D
I N S T A L L A T I O N
**Calculated values.
7.
MAINTENANCE
ACV recommends that the cylinder is maintained by a competent person, this should be carried out every
12 months.
The safety valves must be manually operated at least once a year to check their operation and re-seating.
Allow cylinder to cool before slowly twisting open the temperature and pressure relief valve. The water
should flow freely through the tundish and discharge pipe work, check that the valve reseats when
released.
CAUTION: The water discharged may be very hot.
Repeat the steps above for the expansion relief valve on the cold inlet pipe work.
The pressure reducing valve (PRV) has a strainer that can be removed for inspection and if necessary
cleaning.
i.
Isolate the cold water inlet to the cylinder.
ii.
Open the lowest hot tap to remove the pressure from the system.
iii.
The plastic PRV cartridge can be unscrewed from the brass valve body, loosen using a suitable
spanner (not stilsons or pump pliers) unscrew and pull the cartridge from the valve body, the
strainer will be withdrawn with the cartridge.
iv.
Remove the strainer from the cartridge and clean under running water if necessary.
v.
Replace strainer and push cartridge into valve body, take care when screwing the cartridge in not
to damage the threads. Do not over tighten.
vi.
Close hot tap and slowly open the cold water isolating valve to the cylinder, check for any leaks.
The primary tank should be checked for a build up of air, this can be purged using the primary air vent on
the top of the cylinder. Check the primary system pressure gauge on the boiler or filling loop and recharge
as necessary.
IMPORTANT: If the primary system is being topped up on a regular basis there is a risk of corrosion
damage to the cylinder.
The tank must be fitted by means of screwed couplings or flanges to allow dismantling and removal of the
unit. These should be fitted in such a way as to allow easy access.
8.
PARTS LIST
Description
Control Thermostat
High Limit Thermostat
Manual Air Vent
Thermostat Dry Well 130
Thermostat Dry Well 160
Thermostat Dry Well 210+
Thermostat Dry Well 240+
Thermostat Dry Well 300+
Top Cover
Code
54442045
54764020
55445006
39438027
39438039
39438046
39438047
39438047
497B5010
Description
Cold Inlet Tube 130
Cold Inlet Tube 160
Cold Inlet Tube 210+
Cold Inlet Tube 240+
Cold Inlet Tube 300+
Complete Control Pod (stat to left)
Complete Control Pod (stat in centre)
3kW Immersion (Thermco)
6kW Immersion Single Phase (ACV)
12
Code
497B0003
497B0005
497B0007
497B0009
497B0010
24614152
24614114
OI300
10800083
T E C H N I C A L
A N D
I N S T A L L A T I O N
Bottom Cover
9.
497B5002
6kW Immersion Three Phase (ACV)
TECHNICAL DATA
Type
SLE 130
SLE 160
Code
06618801 06618901
Unvented Kit
Smart Pak1 (12ltr)
Total Capacity (ltrs)
130
161
Heating Fluid Capacity (ltrs)
55
62
Domestic Water Capacity (ltrs)
75
99
Primary press. drop (mbar)
17
22
Immersion heater connection
1½” BSP
1½” BSP
Primary fluid connections
1” BSP
1” BSP
Domestic water connections
¾” BSP
¾” BSP
Dimension: A (mm)
1024
1222
B (mm)
234
234
C (mm)
759
959
D (mm)
234
234
Mains kit will add approximately 500mm to height.
Weight empty (kg)
45
54
Weight full (kg)
175
215
Heating surface (m²)
1.03
1.26
Primary fluid flow (ltrs/hr)
2100
2600
Maximum Absorbed Power (kW)
23
31
Start-up time from 10 to
22
22
85°C(min)
Ozone Depletion Potential
0
0
13
10800084
T E C H N I C A L
A N D
I N S T A L L A T I O N
Global Warming Potential
Losses ΔT50°C (kWh/day)
0.00025
1.92
Type
Code
Unvented Kit
Total Capacity (ltrs)
Heating Fluid Capacity (ltrs)
Domestic Water Capacity (ltrs)
Primary press. drop (mbar)
Immersion heater connection
Primary fluid connections
Domestic water connections
Dimension: A (mm)
B (mm)
C (mm)
D (mm)
E (mm)
F (mm)
G (mm)
0.000025
1.97
SLE+ 210
SLE+ 240
06627301
06627401
Smart Pak1 (12ltr)
203
242
77
78
126
164
37
45
1½” BSP
1½” BSP
1” BSP
1” BSP
¾” BSP
¾” BSP
1493
1741
1230
1477
937
1068
312
303
120
110
352
343
233
233
Mains kit will add approximately 500mm to height.
Weight empty (kg)
66
76
Weight full (kg)
269
318
Heating surface (m²)
1.54
1.94
Primary fluid flow (ltrs/hr)
3500
4200
Maximum Absorbed Power (kW)
39
53
Start-up time from 10 to 85°C(min)
20
20
Ozone Depletion Potential
0
0
14
SLE+ 300
06627501
SmartPak2 (18ltr)
293
93
200
51
1½” BSP
1” BSP
¾” BSP
2046
1783
1278
338
145
378
233
87
380
2.29
5500
68
22
0
T E C H N I C A L
A N D
I N S T A L L A T I O N
Global Warming Potential
Losses ΔT50°C (kWh/day)
0.00025
2.05
0.00025
2.13
0.00025
2.24
10. DISCHARGE PIPE
It is a requirement of Building Regulation G3 that any discharge from an unvented system is conveyed to
where it is visible, but will not cause danger to persons in or about the building. The tundish and discharge
pipes should be fitted in accordance with the requirements and guidance notes of Building Regulation G3.
The G3 Requirements and Guidance section 3.50 - 3.63 are reproduced in the following sections of this
manual. For discharge pipe arrangements not covered by G3 Guidance advice should be sought from your
local Building Control Officer. Any discharge pipe connected to the pressure relief devices (Expansion Valve
and Temperature/Pressure Relief Valve) must be installed in a continuously downward direction and in a
frost free environment. Water may drip from the discharge pipe of the pressure relief device. This pipe
must be left open to the atmosphere. The pressure relief device is to be operated regularly to remove lime
deposits and to verify that it is not blocked.
G3 REQUIREMENT
“...there shall be precautions...to ensure that the hot water discharged from safety devices is safely
conveyed to where it is visible but will not cause danger to persons in or about the building.”
Notes:
Discharge pipe-work D2 can now be a plastic pipe but only pipes that have been tested to a minimum
110°C must be used.
Discharge pipe D2 can now be plumbed into the soil stack but only soil stacks that can handle
temperatures of 99°C or greater should be used.
The following extract is taken from the latest G3 Regulations
Discharge pipe D1
3.50 Safety devices such as temperature relief valves or combined temperature and pressure and pressure
relief valves (see paragraphs 3.13 or 3.18) should discharge either directly or by way of a manifold via a
short length of metal pipe (D1) to a tundish.
3.51 The diameter of discharge pipe (D1) should be not less than the nominal outlet size of the
temperature relief valve.
3.52 Where a manifold is used it should be sized to accept and discharge the total discharge from the
discharge pipes connected to it.
3.53 Where valves other than the temperature and pressure relief valve from a single unvented hot water
system discharge by way of the same manifold that is used by the safety devices, the manifold should be
factory fitted as part of the hot water storage system unit or package.
Tundish
15
T E C H N I C A L
A N D
I N S T A L L A T I O N
3.54 The tundish should be vertical, located in the same space as the unvented hot water storage system
and be fitted as close as possible to, and lower than, the valve, with no more than 600mm of pipe between
the valve outlet and the tundish (Fig. 5 & Table 3, page 10).
Note: To comply with the Water Supply (Water Fittings) Regulations, the tundish should incorporate a
suitable air gap.
3.55 Any discharge should be visible at the tundish. In addition, where discharges from safety devices may
not be apparent, e.g. in dwellings occupied by people with impaired vision or mobility, consideration
should be given to the installation of a suitable safety device to warn when discharge takes place, e.g.
electronically operated.
Discharge pipe D2
3.56 The discharge pipe (D2) from the tundish should:
(a) have a vertical section of pipe at least 300mm long below the tundish before any elbows or bends in
the pipework (see Diagram 1, G3), (Fig. 5, page 10); and
(b) be installed with a continuous fall thereafter of at least 1 in 200.
3.57 The discharge pipe (D2) should be made of:
(a) metal; or
(b) other material that has been demonstrated to be capable of safely withstanding temperatures of the
water discharged and is clearly and permanently marked to identify the product and performance
standard (e.g. as specified in the relevant part of BS 7291).
3.58 The discharge pipe (D2) should be at least one pipe size larger than the nominal outlet size of the
safety device unless its total equivalent hydraulic resistance exceeds that of a straight pipe 9m long, i.e. for
discharge pipes between 9m and 18m the equivalent resistance length should be at least two sizes larger
than the nominal outlet size of the safety device; between 18 and 27m at least 3 sizes larger, and so on;
bends must be taken into account in calculating the flow resistance. See figure, table and the worked
example.
3.59 Where a single common discharge pipe serves more than one system, it should be at least one pipe
size larger than the largest individual discharge pipe (D2) to be connected.
3.60 The discharge pipe should not be connected to a soil discharge stack unless it can be demonstrated
that that the soil discharge stack is capable of safely withstanding temperatures of the water discharged, in
which case, it should:
(a) contain a mechanical seal, not incorporating a water trap, which allows water into the branch pipe
without allowing foul air from the drain to be ventilated through the tundish;
(b) be a separate branch pipe with no sanitary appliances connected to it;
(c) if plastic pipes are used as branch pipes carrying discharge from a safety device they should be either
polybutalene (PB) to Class S of BS 7291-2:2006 or cross linked polyethylene (PE-X) to Class S of BS 72913:2006; and (d) be continuously marked with a warning that no sanitary appliances should be connected to
the pipe.
Note:
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1. Plastic pipes should be joined and assembled with fittings appropriate to the circumstances in which
they are used as set out in BS EN ISO 1043-1.
2. Where pipes cannot be connected to the stack it may be possible to route a dedicated pipe alongside or
in close proximity to the discharge stack.
Termination of discharge pipe
3.61 The discharge pipe (D2) from the tundish should terminate in a safe place where there is no risk to
persons in the vicinity of the discharge.
3.62 Examples of acceptable discharge arrangements are:
(b) to a trapped gully with the end of the pipe below a fixed grating and above the water seal;
(c) downward discharges at low level; i.e. up to 100mm above external surfaces such as car parks, hard
standings, grassed areas etc. are acceptable providing that a wire cage or similar guard is positioned to
prevent contact, whilst maintaining visibility; and
(d) discharges at high level: e.g. into a metal hopper and metal downpipe with the end of the discharge
pipe clearly visible or onto a roof capable of withstanding high temperature discharges of water and 3m
from any plastic guttering system that would collect such discharges.
3.63 The discharge would consist of high temperature water and steam. Asphalt, roofing felt and nonmetallic rainwater goods may be damaged by such discharges.
Extract from ‘The Building Regulations 1991 G3’
Diagram: Typical discharge pipe arrangement
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temperature relief valve to tundish
600mm maximum
Tundish
300mm minimum
Discharge below fixed
grating (3.61 gives
alternative points of
discharge)
Metal discharge pipe (D2) tundish with
continuous fall. See 3.56, Table G3 and
worked example
Fixed grating
Trapped gulley
Table G3 – Sizing of copper discharge pipe ‘D2’ for common temperature relief valve outlet sizes
Valve outlet size
Minimum size of
discharge pipe D1
G½
15mm
G¾
22mm
G1
28mm
Minimum size of
discharge pipe D2
from tundish
22mm
28mm
35mm
28mm
35mm
42mm
35mm
42mm
54mm
Maximum
resistance allowed,
expressed as a
length of straight
pipe (i.e. no elbows
or bends)
Up to 9m
Up to 8m
Up to 27m
Up to 9m
Up to 8m
Up to 27m
Up to 9m
Up to 8m
Up to 27m
Resistance created
by each elbow or
bend.
0.8m
1.0m
1.4m
1.0m
1.4m
1.7m
1.4m
1.7m
2.3m
Worked example of discharge pipe sizing
Fig. 5, page 10: shows a G1/2 temperature relief valve with a discharge pipe (D2) having 4 No. elbows and
length of 7m from the tundish to the point of discharge.
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From Table:
Maximum resistance allowed for a straight length of 22mm copper discharge pipe (D2) from a G1/2
temperature relief valve is 9.0m.
Subtract the resistance for 4 No. 22mm elbows at 0.8m each = 3.2m
Therefore the permitted length equates to: 5.8m
5.8m is less than the actual length of 7m therefore calculates the next largest size.
Maximum resistance allowed for a straight length of 28mm pipe (D2) from a G1/2 temperature relief
valves equates to 18m.
Subtract the resistance of 4 No. 28mm elbows at 1.0m each = 4.0m
Therefore the maximum permitted length equates to: 14m
As the actual length is 7m, a 28mm (D2) copper pipe will be satisfactory.
WARNINGS:
• Under no circumstances should the factory fitted temperature/pressure relief valve be removed
other than by a competent person.
• No control or safety valves should be tampered with or used for any other purpose.
• The discharge pipe should not be blocked or used for any other purpose.
• The tundish should not be located adjacent to any electrical components.
NOTES:
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