Hired-Hand Super-Savers (Forced Air Heaters) XL: SS-225-XL - Manual (Page 20)

4801-5101 Rev 6-09 Page 20 of 26 Super Saver XL CE Heater
11. Pipe Sizing For Sufficient Gas Service
THESE GUIDELINES ARE BASED ON THE U. S. STANDARDS.
REFER TO LOCAL AND NATIONAL LAWS AND PRACTICE WHICH MAY SUPERSEDE THE
FOLLOWING.
1. Using a system schematic, label each
piping section of the system starting at the
meter or regulator. A different pipe
section starts where the gas demand of
the system changes, usually at a junction.
2. Determine the Heating Value Required
(HVR) in kWh (kilowatt hours) for each
section of pipe. HVR = (no. of heaters
supplied with gas by pipe section) x
(heat output per heater)
3. Determine The Equivalent Length Of Pipe (ELOP)
required for sufficient gas service. ELOP =
(length from gas meter to most remote heater)
+ (Minor loss equivalents of the system).
Important: Use the ELOP value from this
equation for size determination of all pipe sections.
4. Use the ELOP value from step 3, and the HVR of
each pipe section to determine the required pipe
size from table ‘Maximum Capacity of Pipe’ for
either Natural Gas (Table 3) or LP (Table 4).
Directions For Reading Pipe Size From Tables:
EXAMPLE: Four 12 kW (40,000 BTUH) heaters will be installed on the gas pipe line as in ‘Arbitrary
Piping System’ diagram.
1. Refer to the pipe sections labeled in ‘Arbitrary Piping System’ diagram below.
2. Determine the HVR value of each pipe section of the system.
3. Determine ELOP:
Length from meter to most remote heater = length from a to e (or g) = 30 meters (m) + 8 m = 38
m. Minor loss equivalents from Table 2 = (1 gate valve) x (1m / valve) + (3 tees) x (4 m / tee) =
13 m ELOP = 38 m + 13 m = 51 m. Round up to nearest value listed in Table 3: ELOP = 60 m.
Pipe Section # Heaters HVR Calculation HVR Value
a-b 4 4 x 12 kW 48 kW
b-c 2 2 x 12 kW 24 kW
c-e 1 1 x 12 kW 12 kW
b-d 1 1 x 12 kW 12 kW
b-f 1 1 x 12 kW 12 kW
c-g 1 1 x 12 kW 12 kW
Table 2 Minor Loss Equivalents
(meters per fitting)
Fitting 52mm IPS 52 mm IPS
Or Smaller To 102 mm IPS
45
° Elbow 1 2
90
° Elbow 2 3
Tee 4 6
Gate Valve 1 1
Angle Valve 9 18
Swing Valve 5 9
IMPORTANT
Arbitrary piping system diagram is for example
only and in no way demonstrates proper heater
placement or gas line configurations. Minor loss
equivalent values will vary depending upon your
system configuration
.
b
Arbitrary Piping System
a c
d
e
f
g
Heaters
Heaters
30 m
8 m
8 m
tees
Gas valve
Gate valve