Field survey of trunk line heating gas leaks in commercial broiler houses

Authors: DAVIS, J - Auburn University; ARNOLD, B - Auburn University; SMITH, C - Auburn University; GRIGGS, K - Auburn University; RUEDA, M - Auburn University; CAMPBELL, J - Auburn University; EDGE, C - Auburn University; Purswell, Joseph - Jody

Submitted to: Applied Engineering in Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/24/2023
Publication Date: 3/24/2023
Citation: Davis, J.D., Arnold, B.D., Smith, C.R., Griggs, K.G., Rueda, M.S., Campbell, J.C., Edge, C.M., Purswell, J.L. 2023. Field survey of trunk line heating gas leaks in commercial broiler houses. Applied Engineering in Agriculture. 39(3):279-283. https://doi.org/10.13031/aea.15470.
DOI: https://doi.org/10.13031/aea.15470

Interpretive Summary: Propane and natural gas are the common sources of heat fuel for broiler houses and fuel supply piping has hundreds of yards of piping and connections. Fuel is distributed throughout the house with a higher pressure main line (10 psi) and then stepped down to a lower pressure line (½ to 5 psi) to the heaters. High-pressure main lines usually run on the outside of poultry houses, exposing them to temperature swings that result in expansion and contraction of the steel piping, increasing the potential for leaks, fuel wastage, safety hazards, and emissions footprint. Leakage measurements were conducted on 101 broiler houses in South Alabama ranging in age from new to over 18 years to evaluate the presence of gas leaks on the high-pressure (10 psi) main line. The total number of connections between the storage tank/meter and the low-pressure step-down regulator ranged from 36 to 170. A soap solution in a hand sprayer was used to spray each connection and evaluate the presence of a leak through bubble formation. The percentage of leaks recorded generally increased with age, however, some newer houses had significant leak percentatges resulting from poor installation practices. Poultry producers should get written verification from the gas line contractor/installer that newly constructed houses are free of leaks before operating the farm and checking for leaks every year thereafter.

Technical Abstract: . A field survey was conducted on 23 farms (101 broiler houses) in South Alabama to evaluate the presence of gas leaks on the high-pressure (10 psi) trunk line. Gas trunk lines usually run on the outside of poultry houses exposing them to temperature swings that cause expansion and contraction of the rigid steel piping. Each threaded connection has the potential to leak. The total number of connections between the storage tank/meter and the low-pressure step-down regulator ranged from 36 to 170. A soap solution in a hand sprayer was used to spray each connection and evaluate the presence of a leak through bubble formation. Houses were categorized into four age groups: I (new construction), II (3 to 8 years), III (9 to 17 years), and IV (18+ years). The number of leaks was evaluated as a percentage of total connections. Percentage data were arcsin transformed prior to analysis as a one-way (age) ANOVA with the MIXED procedure in SAS. Least-square means were separated at P = 0.05 with the PDIFF option. In general, leaks as a proportion of total fittings increased with age categories of I, II, III, and IV (0.5 ± 0.20 %, 4.8 ± 0.10 %, 8.6 ± 0.04 %, 5.1 ± 0.04 %, respectively). However, there were houses in each category with leaks that ranged from 16 to 32 %. Poultry producers should get written verification from the gas line contractor/installer that newly constructed houses are free of leaks before operating the farm. It would be useful for poultry producers to check for leaks annually or biannually to verify system integrity and to monitor any developing leaks.