Page 48 - Gi flipbook June/July 2018

IGEM NEWS | Technical standards

Turning up the pressure

Here our Technical Services team gives you
the lowdown on IGEM’s low pressure work

DURING 2016, following complaints purchased and installed until the
raised by installers to the Standards matter is resolved.
Consultation Forum (SCF), work was The WG has identified areas of
carried out by the gas distribution mutual interest and are concerned
networks (GDNs) to produce an Energy with ensuring the approach of the
Networks Association (ENA) document installer and the emergency service
entitled ‘Gas industry bulletin – provider (ESP) is aligned.
Response to poor pressure reports’. The requirements of the Appliance
This document, provided to the SCF, Safety Regulations need to be
was not seen by the industry group as factored into the provision of gas
satisfying their concerns resulting supplied to premises and the WG also
from incidents of low pressure agreed that the appliance
experienced by installers. As a result, manufacturers’ instructions need to 1. On commissioning of the appliance
the SCF made a request that IGEM properly reflect the design and 2. Following reports of poor pressure/
facilitate a working group to consider capacity of the gas system. Meetings failure to achieve operating pressure
the matter more fully. have taken place to discuss their and/or heat input.
The request from SCF was issues and concerns.
discussed by IGEM’s Technical The WG has also agreed to consider (Note: In all instances where the
Coordinating Committee (TCC) and it what should be the typical load for a appliance inlet pressure cannot be
agreed to form the LP Supply domestic property, which would mirror achieved, ensure pipework is correctly
Working Group. This working group the electricity industry. This is in sized before implementing the
(WG) has met seven times and been response to the increased capacity of ‘Reporting of Low Pressure’ process.)
supported by representatives from domestic appliances, which may reach
across the industry. a point of exceeding the capacity of the RECOMMENDATIONS
The WG agreed that the design of normal sized and operated service. It As soon as practicable when
the gas system remained fit for was considered better to tackle the considering installing an appliance,
purpose for existing appliances, but issue in design rather than at the confirm the outlet pressure of the
that for a new generation of commissioning stage. meter is between 18.5mbar to 25mbar
appliances with increasing net heat The WG has agreed procedures to with all appliances within the property
input coming onto the market it may align the requirements across the operating at a realistic normal load*
provide a challenge. industry and are briefly described here. over a six-minute period. The realistic
The WG has agreed that the normal load is the normal maximum
problem is not a significant issue for CONFIRMING CORRECT operating load for the entire gas
the industry, but that when it does GAS PRESSURE installation in the property for a
occur the procedures in place across There are generally two scenarios period of high demand. To replicate
the industry are different, which when an engineer will be required to this, operate the highest output
leads to the customer not being able confirm the correct gas pressure at appliance at its maximum output (e.g.,
to use the appliance that has been the appliance inlet: for boilers heating or hot water)
dependant on appliance type), all
other heating appliances at maximum
LP gas system design pressures output and any other appliances at 50
LP gas system design pressures per cent load e.g., for hob with four
Network at ECV At the outlet of Inlet to Installation Inlet to the burners, only two are lit.
the meter pipework Appliance
MIP 200.0 STP 82.5 STP 82.5 (Note: Ensure there is enough pressure
u
MOP 75.0 MIP mid 75.0 c at the meter outlet minus the internal
pipework designed pressure loss to
mi
u
LOP 25.0 PLOP 25.0 MOP 25.0 P max 25.0 supply the new appliance with
u
mi
c
MOP 22.6 adequate inlet pressure.)
mi
OP mi 21.0 The WG has agreed a document
DmP 19.0 would be prepared outlining the
u
LOP mi 18.0 LOP c 18.0 output of the work done which will be
P min 17.0 circulated to the industry for
DmP 15.0 DmP 15.0 P ign 14.0 comment. This is expected to be
mi
c
available in summer 2018. ■
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IGEMNews_TechnicalStandards.indd 1 17/05/2018 14:32