Concord CXA/H -
Installation and Servicing
7
GENERAL
In practice the deposition of these salts is liable to cause noises
from the boiler body or even premature boiler failure. Corrosion
and the formation of black iron oxide sludge will ultimately result
in premature radiator failure.
Open vented systems are not completely sealed from the
atmosphere if proper venting and expansion of system water is
to be achieved. The same tank is used to fill the system with
water and it is through the cold feed pipe that system water
expands into the tank when the boiler passes heat into the
system. Conversely, when the system cools, water previously
expelled is drawn back from the tank into the system together
with a quantity of dissolved oxygen.
Even if leakage from the heating and hot water system is eliminated
there will be evaporation losses from the surface of the tank which,
depending upon ambient temperature, may be high enough to
evaporate a large portion of the system water capacity over a full
heating season.
There will always be corrosion within a heating or hot water system
to a greater or lesser degree, irrespective of water characteristics,
unless the initial fill water from the mains is treated. Even the
water in closed systems will promote corrosion unless treated.
For the reason stated,
Caradon Ideal Limited
strongly recommend
that, when necessary, the system is thoroughly cleaned, prior to
the use of stable inhibitor, which does not require continual topping
up to combat the effects of hardness salts and corrosion on the
heat exchangers of the boiler and associated systems.
Caradon Ideal Limited
advise contact directly with specialists on
water treatment such as:
Fernox Manufacturing Co. Ltd., or
Tandem House,
Marlowe Way,
Croydon.
Surrey CRO 4XS
Tel 0870 601 5000
Pressure vessels used must comply with BS. 4814 and must
be sized on the basis of the total system volume and initial
charge pressure.
Initial minimum charge pressure should not be less than 0.5
bar (7.2 psi) and must take account of static head and
specification of the pressurising equipment. The maximum
water temperatures permissible at the point of minimum
pressure in the system are specified in Guidance Note PM5.
When make-up water is not provided automatically it will be
necessary to fit controls which shut down the plant in the event
of the maximum system pressure approaching to within 0.35
bar (5 psi) of safety valve setting.
Other British Standards applicable to commercial sealed
systems are:-
BS. 6880: Part 2.
BS. 1212
BS. 6281: Part 1
BS. 6282: Part 1
BS. 6283: Part 4
Working pressure 6 bar maximum.
Particular reference should be made to BS. 6644: Section 6
and Guidance note PM5 "Automatically controlled steam and
hot water boilers" published by the Health and Safety
Executive.
The information and guidance given below is not intended to
override any requirements of either of the above publications or
the requirements of the local authority, gas or water
undertakings.
In general commercial closed pressurised systems are
provided with either manual or automatic water make up.
On both instances it will be necessary to fit automatic controls
intended to protect the boiler, circulating system and ancillary
equipment by shutting down the boiler plant if a potentially
hazardous situation should arise.
Examples of such situations are low water level and operating
pressure or excessive pressure within the system. Depending
on circumstances, controls will need to be either manual or
automatic reset. In the event of shutdown both visual and
audible alarms may be necessary.
requirements of the Gas Safety Regulations, current I.E.E.
(BS.7671) Regulations, Model Water Bye-laws, local water authority
bye-laws and it should also comply with any relevant requirements
of the local gas region, local authority and the relevant British
Standard Codes of practice and building regulations.
FOR SMALL PIPE INSTALLATIONS
BS. 6891;
Installation of low pressure pipework
FOR LARGE PIPE INSTALLATIONS
Gas Installations
IGE-UP-1:
Purging Procedures of Non-domestic Gas
Installations. Soundness Testing Procedures
for Industrial and Commercial.
IGE-UP-2:
Guidance notes on the Installation of Gas
Pipework, Boosters and Compressors in
Customer’s Premises Equal to or Greater than
25mm (Non-domestic).
IGE-UP-10:
Installation of Gas Appliances in Industrial and
Commercial Premises.
BS.6644:
Installation of Gas Fired Hot Water Boilers
70kW to 1.8MW (net).
BS 6880 Pt 1-3: Water Supply.
CP342:2:
Centralised Hot Water Supply.
Model Water Bye-laws
Manufacturers notes must not be taken, in any way, as overriding
statutory obligations.
FOUNDATION
The boiler must stand on a non-combustible floor (i.e. concrete
or brick) which must be flat, level and of a suitable load bearing
capacity to support the weight of the boiler (when filled with
water) and any ancillary equipment.
If the boiler is mounted on a plinth then the dimensions must
exceed the plan area of the boiler by at least 75mm on each
side.
4
SEALED (PRESSURISED) SYSTEMS
INSTALLATION REQUIREMENTS
The appliance must be installed by a CORGI registered installer.
The installation of the boiler must be in accordance with the relevant
Sentinel Division
Betz Dearborn Ltd.,
Widnes,
Cheshire, WA8 8UD
Tel. 0151 424 5351.
157290-3.pmd
11/7/2005, 11:09 AM
7
Содержание Concord CXA 40/H
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