Spirax Sarco BCS1 Pipeline Set Installation and Maintenance Instructions

4030051/3
IM-P403-55
AB Issue 3
BCS1
Pipeline Set
Installation and Maintenance Instructions
General safety information
Your attention is drawn to Safety Information Leaflet IM-GCM-10, as well as to any National
or Local Regulations concerning boiler blowdown. In the UK, guidance is given in HSE
Guidance Note PM60.
WARNING
This pipeline set is for use with one of several Spirax Sarco blowdown controllers. The
controllers comply with various Emissions and Immunity Standards. Full information is
given in the controller Installation and Maintenance Instructions supplied with each unit.
Blowdown
from boiler
Model 10
ball valve
¼" BSP plug
BCV1
blowdown valve
Fig 12 strainer
PT2 plug tail
CP10 sensor
S10 sensor chamber
LCV1
Check valve
Model 10
ball valve
Fig. 1 General layout
Printed in the UK
Blowdown
to heat recovery system
© Copyright 2005
Description
Components in this pipeline set have been
selected to enable straightforward installation
of a blowdown system where the probe is to be
mounted in the pipeline.
To
blowdown
system
The BCS1 pipeline set consists of the
following items:1
1
1
1
1
1
1
2
-
S10 sensor chamber ½" BSP.
CP10 sensor and gasket.
PT2 Plug tail.
Sensor chamber plug ¼" BSP.
BCV1 solenoid valve ½" BSP 230 V.
LCV1 check valve ½" BSP
Fig 12 SG iron strainer ½" BSP.
Model 10 CS ball valve ½" BSP.
A controller is also required, and should be
selected from the Spirax Sarco range.
The controllers offer a variety of features which
are described in separate literature.
Boiler with
side connection
Horizontal
shell boiler
Bottom blowdown valve
Fig. 2 Blowdown from side connection
Operation
The blowdown system works by opening the blowdown valve periodically in order to purge the
system and allow a flow of boiler water past the sensor.
The controller measures the electrical conductivity of the water, which is directly related to the
level of total dissolved solids, or TDS.
The measured value is compared with the set point in the controller.
If the measured value is lower than the set point the blowdown valve closes at the end of the
purge time.
If the measured value is higher than the set point the controller holds the blowdown valve open,
allowing the contaminated boiler water to be replaced by clean, low TDS make-up water.
The blowdown valve closes when the conductivity of the boiler water drops below the controller
set point.
WARNING
With some small boilers, an excessive purge time may lower the water level
significantly, and may even trigger a low water alarm.
Electrical installation
Wiring of the controller, blowdown valve, and
sensor is described in the Installation and
Maintenance Instructions supplied with each
item. Copies are available on request.
Mechanical installation
General
Unpack the system, read and keep the
Installation and Maintenance Instructions
provided with the individual items. They will be
needed for future maintenance.
It is strongly recommended that, wherever
possible, the blowdown system is connected
to a boiler side connection, well away from the
boiler feedwater inlet. This minimises the
chance of suspended solids entering the
2
Vertical boiler
Boiler
with no side
connections
To
blowdown
system
Bottom
blowdown valve
Fig. 3 Blowdown from bottom connection
IM-P403-55 AB Issue 3
Note: Consider larger strainer and
pipe for conditions where suspended
solids are likely to be a problem.
Sensor and sensor chamber
TDS blowdown control valve
Ball valve
Ball valve
Boiler
Strainer
Ø 15 mm
pipe
Check
valve
300 mm
(12")
Bottom blowdown valve
Fig. 4 Installation where no side connection is available and suspended solids are likely
blowdown system strainer, and ensures that a representative sample of boiler water is taken.
See Figure 2.
If a side connection is not possible and a 'T' connection has to be taken from the main bottom
blowdown pipe, make the connection at the top of the pipe, as near as possible to the boiler, before
the bottom blowdown valve. Figure 3. If a high level of suspended solids is likely, (old boiler or
less than adequate water treatment) ensure the 'T' connection is the same diameter as the
blowdown line for 300 mm (12"), then fit a reducer to ½" pipe.
It may also be useful to consider the use of a larger strainer than the one provided, as shown
in Figure 4.
The strainer provided in the kit has 0.8 mm screen perforations. Do not fit a strainer screen finer
than that provided as it may become blocked prematurely.
Install the system components in the order shown in Figure 5, using ½" BSP connectors and
PTFE tape.
Union fittings are recommended to allow easy removal of the assembly.
Strainer
Install with the flow in the direction of the arrow with the end cap downwards. Do not overtighten
connectors.
Blowdown
valve
Blowdown
from boiler
Ball
valve
Strainer
Union
Ball
valve
Check
valve
Sensor in
chamber
Union
Blowdown to heat
recovery system
Fig. 5 Typical installation
IM-P403-55 AB Issue 3
3
S10 sensor chamber
Install the sensor chamber upstream of the blowdown valve, as close to the boiler as possible,
either horizontally, or vertically with the flow upwards. The 2" BSP sensor connection should
be horizontal so that the sensor may be fitted from the side.
A sample cooler may be connected to the ¼" BSP connection on the sensor chamber for boiler
water sampling. If not used, it must be plugged with the ¼" BSP plug provided.
CP10 sensor and PT2 plug tail.
Fit the joint gasket and tighten the sensor to a torque of 50 - 56 N m (37 - 41 Ibf ft).
We do not recommend the use of PTFE tape on the thread, but a graphited or copper based sealing
compound may be used to aid subsequent removal. Fit the plug tail using the gasket provided.
Do not overtighten the union nut. When mechanical protection of the cable is required, the end
nut may be removed from the plug tail and the M16 thread used to fit a flexible conduit adaptor.
Blowdown valve
Install with the flow in the direction of the arrow, in a horizontal pipeline, with the solenoid vertically
above the valve. Do not overtighten the connectors into the brass body. For ease of installation
the solenoid unit may be moved through 360° by slackening the top nut. The cable socket insert
can also be repositioned if required.
Lift check valve
Install with the flow in the direction of the arrow, in a horizontal pipeline with the screwed cap on
top. Do not overtighten the connectors.
Ball valves
May be installed in any plane with flow in either direction. Ensure that there is space available for
free movement of the lever.
WARNING
National Regulations may call for a special type of isolating valve at the boiler shell.
Discharge pipework
In the UK and many other countries, for single boiler installations the blowdown may discharge
into the bottom blowdown line downstream of the bottom blowdown valve.
For multi-boiler installations the blowdown pipelines must be kept separate from the bottom
blowdown lines up to the blowdown vessel. For further information in the UK see Health and Safety
Executive Guidance Note PM60.
WARNING
Other regulations or Guidance Notes may apply outside the UK.
Maintenance
Controllers require no maintenance.
The blowdown system, however, should be checked as follows:Weekly
Take a sample of the boiler water through a sample cooler and measure its TDS, or conductivity.
The Spirax Sarco MS1 is a suitable instrument for this purpose.
Carry out a manual purge of the system.
Check that blowdown is actually discharged (e.g. by temperature or sound) and that the blowdown
valve shuts off fully.
Operate the stop valves to ensure they shut off and are not seized or stiff.
Annually
Isolate the system (or empty the boiler), inspect and service the system components as
described in their relevant Installation and Maintenance Instructions.
Severe operating conditions
Where it is suspected that scaling may be taking place, or where water quality is suspect, it may
be necessary to increase the frequency of servicing.
Inspect the strainer, valves and sensor every month initially, increasing or decreasing intervals
according to the degree of contamination found.
Always consult the local competent boiler authority for advice on the frequency of boiler
inspections.
4
IM-P403-55 AB Issue 3