The form of priming arrangement heretofore used, with metal check
valves, one main 2-inch priming valve, and 1-inch priming pipes,
separate controllable air cocks, may be retained on all pumps at
present in service, and will be considered satisfactory, if kept in
good order.
If in any case such checks give trouble the priming arrangement may
be changed and valves like Fig. 14 or rubber checks as described
in sections _f-j_, made up in detachable form,[D] may be put on if
desired, where the connections on the pump permit them.
Where neither method is desired or where neither is feasible the faulty
checks may be replaced by a special type such as are now made for
this use, by the Locke Regulator Company, of Salem, Mass. These are
1-inch check valves, adapted to use a small disc of medium hard rubber,
similar to a pump valve.
These fittings are very near the dimensions of the commercial check
valve, so that with slight shortening of piping connections they will
fit into the present arrangements, and give satisfaction.