Brochure

Gastite Division, Titeflex Corporation
1116 Vaughn Parkway / Portland, TN 37148
800.662.0208 / www.gastite.com / [e-mail]
40
April 2015
Section 3: System Configuration
3.2.12 Example 11 - Commercial Hybrid System – 7"WC
Figure 3-19 below shows a multi-level apartment building. e piping is arranged
in vertical parallel fashion, with individual CSST appliance runs supplied by
distribution manifolds. e main trunk line (“A”-“D”) from the meter to the
distribution manifolds is rigid pipe rather than CSST. e utility company’s supply
pressure (downstream of the meter) is 7"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 2"WC (supply pressure 7"WC – appliance requirement 5"WC). Note: Rigid
pipe sized using a 0.5"WC pressure drop table as no 2.0"WC pressure drop table for rigid
pipe is available.
Table 3-12
Section Description Load Delivered by Section
Section
Length
Run
Length
Tube Size
“A” – Rigid Trunk 412 CFH = 412,000 BTUH 5 feet 60 feet 1-1/4" Rigid
“B” – Rigid Trunk 309 CFH = 309,000 BTUH 10 feet 60 feet 1-1/4" Rigid
“C” – Rigid Trunk 206 CFH = 206,000 BTUH 10 feet 60 feet 1" Rigid
“D” – Rigid Trunk 103 CFH = 103,000 BTUH 10 feet 60 feet 3/4" Rigid
“E1” – Dryer 28 CFH = 28,000 BTUH 20 feet 20 feet 3/8" CSST
“F1” – Fireplace 25 CFH = 25,000 BTUH 25 feet 30 feet 1/2" CSST
“G1” – Water Heater 50 CFH = 50,000 BTUH 15 feet 20 feet 1/2" CSST
“E2” – Dryer 28 CFH = 28,000 BTUH 15 feet 30 feet 3/8" CSST
“F2” – Fireplace 25 CFH = 25,000 BTUH 25 feet 40 feet 1/2" CSST
“G2” – Water Heater 50 CFH = 50,000 BTUH 15 feet 30 feet 1/2" CSST
“E3” – Dryer 28 CFH = 28,000 BTUH 15 feet 40 feet 3/8" CSST
“F3” – Fireplace 25 CFH = 25,000 BTUH 25 feet 50 feet 1/2" CSST
“G3” – Water Heater 50 CFH = 50,000 BTUH 15 feet 40 feet 1/2" CSST
“E4” – Dryer 28 CFH = 28,000 BTUH 15 feet 50 feet 3/8" CSST
“F4” – Fireplace 25 CFH = 25,000 BTUH 25 feet 60 feet 1/2" CSST
“G4” – Water Heater 50 CFH = 50,000 BTUH 15 feet 50 feet 1/2" CSST
Run Length for Trunk Sections = Distance from meter to furthest appliance (Longest Run)
Run Length for Appliance Sections = Distance from meter to each appliance
SIZING RUN “A”
• Run “A” is sized by the total load of all appliances and the run length from the meter to the furthest appliance
• e total load of all appliances is 4 x (50 + 25 + 28) = 412CFH
• e run length to the 4th floor Fireplace (furthest appliance) is 5 + 10 + 10 + 10 + 25 = 60ft
• Referring to Table 7-23 (Rigid pipe 0.5"WC pressure drop): for a 60ft run, 1-1/4" pipe has a capacity over 412CF (actual: 530)
SIZING RUN “B”
• Run “B” is sized by the load of the supplied appliances and the run length from the meter to the furthest appliance
• e total load of the supplied appliances is 3 x (50 + 25 + 28) = 309CFH
• e run length to the 4th floor Fireplace (furthest appliance) is 5 + 10 + 10 + 10 + 25 = 60ft
• Referring to Table 7-23 (Rigid pipe 0.5"WC pressure drop): for a 60ft run, 1-1/4" pipe has a capacity over 309CF
(actual: 530)
Fig. 3-19