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Permeation of gasoline through DI pipe gaskets in water mains
Author(s) -
Cheng ChuLin,
Gaunt James A.,
Mao Feng,
Ong Say Kee
Publication year - 2012
Publication title -
journal ‐ american water works association
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.466
H-Index - 74
eISSN - 1551-8833
pISSN - 0003-150X
DOI - 10.5942/jawwa.2012.104.0052
Subject(s) - gasket , natural rubber , gasoline , permeation , neoprene , materials science , sorption , ethylbenzene , styrene butadiene , toluene , xylene , waste management , composite material , styrene , chemistry , polymer , organic chemistry , membrane , copolymer , adsorption , biochemistry , engineering
Sorption tests and pipe‐drum experiments were conducted to study permeation of monoaromatic compounds in gasoline through five polymeric materials used in ductile‐iron (DI) pipe gaskets. Ethylene propylene diene monomer (EPDM) had the highest sorption of premium gasoline, and fluoroelastomer rubber had the lowest. A comparison of gaskets' heel and bulb portions found that the heel sorbed less gasoline, suggesting greater resistance to permeation. Pipe‐drum experiments showed that the order of breakthrough of benzene‐toluene‐ethylbenzene‐xylene compounds for gaskets exposed to premium gasoline was EPDM > chloroprene rubber ≈ styrene butadiene rubber (SBR) > nitrile rubber (NBR). For DI pipes with SBR gaskets exposed to premium gasoline, the benzene concentration after 8 h of stagnation exceeded the maximum contaminant level (MCL). With typical water flow rates in pipes, the estimated benzene concentration did not exceed the MCL. If pipes are to be installed in gasoline‐saturated groundwater, NBR gaskets are preferred over SBR gaskets.