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9 NPT threaded <br />connections <br />r-----------� <br />1 On bell x female adapters, use <br />pipe wrench over threaded <br />portion only. On bell x male <br />1 adapters, use pipe wrench on 1 <br />steel nipple whenever possible. <br />L ----------- J <br />r----------- i <br />In general, threaded connections <br />should be made up before <br />adhesive -bonded joints to I <br />minimize the possibility of <br />damage to bonded joints caused <br />by torquing the threaded <br />connections. However, when 1 <br />1 installing molded threaded 1 <br />bushings (tapered major nominal <br />1 pipe size x threaded minor 1 <br />nominal pipe size) make the <br />1 tapered bonded joint first and <br />1 allow it to cure before making up 1 <br />the threaded joint. This order of <br />I joint make-up will prevent <br />damage to the bushing. 1 <br />L----------- J <br />r-----------� <br />Never use a pipe wrench directly <br />on the pipe: wrench up only on <br />adapters. <br />L -----------J <br />Fig. 9-1. The Ameron fiberglass - <br />reinforced isolation adapter is mounted <br />between the flex connector and the <br />shear valve. <br />Thread preparation <br />• Inspect threads on fiberglass adapters and threaded bushings. <br />Do not use if threads are damaged. <br />• Inspect threads on steel fittings for burrs. <br />• Remove burrs from steel fittings by making up to mating steel threads. Unmake <br />the steel fitting and reinspect. <br />• Always dry fit fiberglass and steel threads without sealing compound. It should be <br />possible to dry fit the threads as shown in the following table. If the proper <br />number of threads cannot be made up, select a new steel fitting. <br />Making the joint <br />Threads must be clean and dry before applying thread -sealing compound. <br />• Use a nonhardening, solvent -free Teflon based thread sealant such as Jomar <br />Seal "The Heavyweight' or Gasoila Soft Set pipe sealant. <br />• Apply sealing compound to male and female threads. <br />• Hand tighten the joint, then <br />use a wrench to get full <br />make-up. Standard pipe <br />wrenches can be used with <br />care on fiberglass adapters. <br />Do not overtighten. <br />• The parts should make up <br />the number of threads <br />shown in the table above. <br />Otherwise, a proper seal <br />may not be effected when <br />tightened. <br />Threads to Dry Fit and to Seal <br />Nominal <br />Pipe Size <br />Threads to <br />Additional <br />(in) (mm) <br />Dry Fit <br />Threads to Seal <br />1 l 40 <br />4-5 <br />3 <br />2 50 <br />4-5 <br />3 <br />3 80 <br />5-6 <br />3 <br />4 100 <br />6-7 <br />2 <br />Isolating flex connectors at the shear valve <br />When flex connectors are directly buried at the dispenser, regulations frequently require <br />that they be cathodically protected and provisions be made to avoid stray current <br />electrolysis and corrosion. In such cases the flex connector must be electrically isolated <br />from the shear valve and from other metallic components in the system. Experience has <br />shown that nylon isolation adapters do not perform well inasmuch as the poor <br />mechanical strength of the material results in creep or thread deformation with <br />subsequent leakage. <br />Ameron manufactures a 1'h NPT female x 11h NPT male fiberglass -reinforced isolation <br />adapter which maybe mounted between the flex connector and the shear valve. Follow <br />the same general installation procedures as with other NPT threaded fittings. After <br />applying the sealing compound, hand tighten the adapter. Final make-up requires 11h <br />to 2 additional turns. <br />i Shear valve <br />L� 1'k NPT female <br />�- 2'/e —10- Vh NPT Dualoy isolation <br />f male adapter <br />13/8 4 <br />MA <br />21'/a LJ I <br />�� SS flex connector <br />11h NPT male <br />both ends <br />11h NPT (by others) <br />female <br />n <br />