API STD 677:2006 pdf download

API STD 677:2006 pdf download

API STD 677:2006 pdf download.General-Purpose Gear Units for Petroleum, Chemical and Gas lndustry Services.
Note: Small gearboses may not accommodate this size filter-breather. Alternate configurations shall be as mutually agreed between the purchaser and senior. Refer to API Std 614. Appendis E. for definition of tihration rating. II specified, a non-replaceable. cleanable filter-breather shall he provided constructed of stainless steel with stainless steel or copper-nickel alloy internals, and shall be designed and located to prevent entrainment or discharge of oil to the atmosphere. pressure buildup in the casing. entrance of water during violent rainstorms, and entrance of dirt entrained in the air. The filtcr.breather connection shall he at least 3/4 NFl’. and its construction shall permit easy disassembly for inspection and cleaning.
Note: The conventional filter breather as described in this paragraph may permit contaminated air to be drawn into the gear case and contaminate the oil. If specified by the purchaser and accepted by the vendor, gear unit casings shall be provided with purge oil mist to prevent casing contamination from environmental [actors.
Note: This requires the oil mist lubricant to he the same as the main lubricant for the gear unit to prevent oil quality degradation. Careful consideration should be given to how the gear unit reservoir oil level, whether the reservoir is integral in the sunip or on an external console, ssould be maintained where oil mist condensation is a possibility. A removable, ga.sketed inspection cover or covers shall he provided in the gear casing to permit direct visual inspection of the full-face width of the gear elements. The inspection opening or openings shall preferably be at least one-half the width of the gear face. Permanent coatings or paint shall not be applied to the interior of the casing unless the purchaser approves in advance the material and method of application. On units that have pressurited oil systems with pitch line velocities above IS rn/s (3.000 filinin). the gearbos casing shall he designed so that the gears do not dip into the oil during operation or upon shutdown. Gear units ator below 15 rn/s (3.000 ft/mm) pitch line velocity may dip into the oil: however, above 10 rn/sec (2,0(X) ft/mm) pitch line velocity, an oil pan shall be used to ensure rapid drainage and to minimize foaming.
2.5.2 Joints
Casing splitlines shall use a metal-to—metal joint (with a suitable joint compound) that is tightly maintained by suitable bolting. Gaskets (including string-type) shall not be used on splitlincs for parallel shaft gears.
Note: Due to the interaction of the rotating elements of spiral bevel gear units, it is normally required that the clement’s mounting distances be adjustable to achieve proper tooth mesh contact and backlash, When the adjustment is made by shifting axially, in line with the clement’s shaft center line of rotation by use of a combination housing cover-bearing carrier, shim type gaskets are permitted.
2.5.3 Bolting Case bolting may be of the through-bolt, studded, or cap-screw type. Threaded bolt holes shall not penetrate through the wall into the interior of the casing. Disassembly shall not require removal of studs.