_API_Spec_11S1-1997_2008.pdf

FOREWORDThis recommended practice is under the jurisdiction of the American Petroleum Institute(APD)Subcommittee on Field Operating Equipment.This recommended practice shall become effective on the date printed on the cover butmay be used voluntarily from the date of distribution.API publications may be used by anyone desiring to do so.Every effort has been made bythe Institute to assure the accuracy and reliability of the data contained in them;however,theInstitute makes no representation,warranty,or guarantee in connection with this publicationand hereby expressly disclaims any liability or responsibility for loss or damage resultingfrom its use or for the violation of any federal,state,or municipal regulation with which thispublication may conflict.Suggested revisions are invited and should be submitted to the director of the Explorationand Production Department,American Petroleum Institute,1220 L Street,N.W.,Washing-ton,D.C.20005.