_e._ The thickness of metal for cylinder shell, valve decks, partitions, ribs, etc., will depend largely upon the form of construction, but, in a general way, to establish safe minimums for the average water cylinder, of nearly cylindrical form, whose flat surfaces are stiffly ribbed, we submit the table below: =========================+==========+==========+============+============ =Size of Pump.= |=500 gal.=|=750 gal.=|=1,000 gal.=|=1,500 gal.= -------------------------+----------+----------+------------+------------ Thickness of cylinder | Inches. | Inches. | Inches. | Inches. shell when of nearly | | | | cylindrical form | 7/8 | 1 | 1-1/8 | 1-1/4 | | | | Thickness of valve decks | | | | when well ribbed | 1-1/4 | 1-1/4 | 1-1/4 | 1-1/4 | | | | | | | | Thickness of transverse | 1-1/4 | 1-1/4 | 1-1/2 | 1-1/2 partition, depending | to | to | to | to on ribbing | 1-1/2 | 1-1/2 | 2 | 2 | | | | Thickness of longitudinal| 1-1/4 | 1-1/4 | 1-1/4 | 1-1/2 partition, depending on| to | to | to | to ribbing | 1-1/2 | 1-1/2 | 2 | 2 | | | | Thickness of ribs | 3/4 | 7/8 | 1 | 1 | | | | Thickness of suction | | | | chamber | 5/8 | 3/4 | 3/4 | 7/8 | | | | Thickness of delivery | | | | chamber | 7/8 | 1 | 1-1/8 | 1-1/4 | | | | -------------------------+----------+----------+------------+----------- Lighter construction than herein specified will not be regarded as satisfactory, and any construction will be finally passed upon on examination of drawings. _f._ The bolting of all parts of the water end is to be of such strength that the maximum stress at bottom of screw thread will not exceed 10,000 lbs. per square inch (disregarding for the moment the initial stress due setting up nuts) for a water pressure of 200 lbs. per square inch, computed on an area out to centre line of bolts. No stud or bolt smaller than 3/4-inch should be used to assemble parts subject to the strain of water pressure, as smaller bolts are likely to be twisted off.