Municipal Products

Stealth Valve

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Free Standing Torque Tubes

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General Assembly :

All torque tubes shall be fabricated preventing the weight of the inner and outer tube from being transmitted to the valve shaft. All inner and outer tubes shall be manufactured in a steady rest and machined finished and faced with all mounting flanges suitable for gasket sealing. Designs causing stagnant water are unacceptable. Torsional deflection calculations shall be submitted with all bids. All welds shall be continuous and full penetration. All torque tubes shall incorporate a permanent stainless steel tag with the maximum allowable torque to be applied to the assembly. All inner shafts shall be supported and designed for removal from the valve shaft while under static pressure. Valve packing retaining plates shall be incorporated in all designs. All torque tubes shall be designed and manufactured in Canada by Stealth International or reviewed equivalent.

Inner Torque tube:

All inner torque tubes shall be designed for a maximum allowable torsional deflection of .50 degrees over the total required length. Both male and female hubs shall be 316 stainless steel, machined on the O.D., and inserted into the inner pipe a minimum of 75 M.M. (3 inches). All hubs shall be shouldered and fitted to the pipe prior to welding. The male hub shoulder O.D. shall be recessed below the outer tube mounting flange. The female hub length shall be equivalent to the valve shaft height in all cases. The Female hub shall be bored through and double keyed at 90 degrees and engage the entire length of the valve shaft. Blind or capped hubs are not acceptable. When acceptable, all inner torque tubes requiring HDG shall be drilled to prevent explosion. Stainless steel inner torque tubes do not require HDG.

Outer Torque Tube:

All outer torque tubes shall be designed for a maximum allowable torsional deflection of .50 degrees over the total required length. Both mounting flanges shall be aligned to suit the Valve and Actuator bolt patterns on the same axis. Both flanges shall be machined stepped to accommodate the pipe O.D. prior to welding. The upper mounting flange shall be designed to guide the inner male hub with a maximum clearance of 3.2 M.M. (.125 inches). All outer housing flanges shall be machined faced after assembly. Based on the valve design and mounting trunnion, the upper or lower flange shall incorporate an additional load bearing thrust flange or recess to accommodate the pre assembly of the inner torque tube. The thrust flange shall be 316 stainless steel and incorporate 316 stainless recessed steel mounting hardware. All length's exceeding 6.5 meters shall be coupled using flanges at each length and bolted as an assembly in the field. The internal drive between the connection shall be single key male and female hubs. The flange connection will not serve as the positive drive. Stealth International Inc shall manufacture all torque tubes.