Potterton NXR4 Installation, Operation & Maintenance Manual page 4

POTTERTON COMMERCIAL PRODUCTS DIVISION
INSTALLATION, OPERATION & MAINTENANCE MANUAL
NXR4
1 FUEL CONSUMPTION
Gas fuel consumption is based on natural gas with a
gross calorific value of 38.6MJ/m
should be corrected for meter supply pressure
particularly on high pressure supplies to prevent
overfiring.
Fuel oil consumption is based on Class D (35
second) gas oil with a calorific value of 58.24 MJ/lit
and a density of 0.855 kg/lit, Kerosene (Class C2)
has a calorific value of 53.22 MJ/lit and a density of
0.795 kg/lit.
2 MINIMUM OPERATING PRESSURE
This is the minimum operating pressure of the boilers
with pumps operating (NOT static pressure). The
requirements of the Health & Safety Executive
guidance note PM5 regarding maximum operating
temperatures should be observed.
3 BOILER FLUE CONNECTION
This is the nominal flue size of the flue connection
spigot, for dimensional details of the flue connection
spigot see Fig.1. Actual flue size required to achieve
correct draught and operation under all running
conditions may need to be increased.
4 FLUE GAS VOLUME
Flue gas volumes are given at STP (standard
temperature and pressure [15°C and 1013.25 mbar]).
Typical flue gas temperatures are given in Table 2.
5 NATURAL VENTILATION
The sizes indicated are free grille areas and are
based on a single boiler installation.
6 MECHANICAL VENTILATION
The volume given is for a single boiler installation.
7 CONNECTION SIZES
The boiler water connections are flanged with 5"
PN16 welded counter flanges provided.
8 WATER FLOW RATES
Water flow rates are given for boiler flow and return
temperature differences of 11°C.
9 COLD FEED/OPEN
SIZES
3
. The gas rate
VENT/SAFETY VALVE
Sizes indicated are minimum sizes for single boiler
installations.
10 MINIMUM RETURN TEMPERATURE
If system return temperatures below 55°C are
required then contact the Potterton Commercial
Technical Department.
11 WEIGHT
The dry weight is exclusive of the burner and gas
train. Each section measures approximately 1220mm
(high) x 860mm (wide) x 150mm (deep) and weighs
135kg (front), 142kg (inter), 160.5kg (rear).
ANY PERSON OR
LIFTING SHOULD BE TRAINED IN MANUAL
HANDLING TECHNIQUES AND IF NECESSARY
USE SUITABLE LIFTING EQUIPMENT TO REDUCE
THE RISK OF INJURY TO THEMSELVES OR
OTHER PEOPLE.
SECTION 1
PAGE 3
PERSONS MOVING OR