Brochure

Gastite Division, Titeflex Corporation
1116 Vaughn Parkway / Portland, TN 37148
800.662.0208 / www.gastite.com / [e-mail]
35
April 2015
Section 3: System Configuration
3.2.10 Example 9: Summation Method for Series System – 6"WC
Figure 3-17 below shows the same house and piping system as Example 1. e piping is arranged in series with a main
run branching at the appliances. e utility company’s supply pressure (downstream of the meter) is 6"WC. e utility
company advises that the specific gravity of the gas delivered will be 0.60 and the energy content is 1 CFH = 1000 BTUH.
e allowable pressure drop across the system has been determined to be 1.0"WC (supply pressure 6"WC - appliance
requirement 5"WC).
When using the “Summation Method” for gas pipe sizing, the sum of the pressure losses through each section of pipe should
result in a minimum 5"WC pressure delivered to the appliance inlet. (Pressures less than 5"WC may be sufficient for proper
appliance operation but should be reviewed with the manufacturer’s input rating and the local administrative authority).
Table 3-10
Section Description Load Delivered by Section Section Length Tube Size
“A” – Trunk 221 CFH = 221,000 BTUH 40 feet 1" CSST
“B” – Trunk 141 CFH = 141,000 BTUH 5 feet 1" CSST
“C” – Trunk 105 CFH = 105,000 BTUH 10 feet 1" CSST
“D” – Trunk 53 CFH = 53,000 BTUH 10 feet 3/4" CSST
“E” – BBQ 25 CFH = 25,000 BTUH 5 feet 1/2" CSST
“F” – Furnace 80 CFH = 80,000 BTUH 10 feet 3/4" CSST
“G” – Water Heater 36 CFH = 36,000 BTUH 10 feet 1/2" CSST
“H” – Range 52 CFH = 52,000 BTUH 10 feet 3/4" CSST
“J” – Dryer 28 CFH = 28,000 BTUH 5 feet 1/2" CSST
SIZING RUN “A”
• Run “A” is sized by the total load of all appliances and the section length
• e total load of all appliances is 80 + 36 + 52 + 28 + 25 = 221CFH
• e section length is 40ft
• Referring to Table 7-21 (Pressure drop per foot for FlashShield™ CSST): for a 225CFH load, 1" CSST has a drop of
0.014"WC per ft. e pressure drop over Run “A” is: 0.014" x 40ft = 0.560"WC
• e available pressure at the end of run “A” is 6"WC - 0.560"WC = 5.440"WC
Fig. 3-17