API St 677:2006(2010) pdf download

API St 677:2006(2010) pdf download.General-Purpose Gear Units for Petroleum, Chemical and Gas Industry Services.
2.7.2 Ouahty Assurance
2.7.2.1 Each pair of mating gears for parallel shalt units shall have a contact check in die gear casing at the vendor’s shop. Those gear sets operating above 20 mJx4,(fl) ftmini pitch line velocity shall he checked for contact on a contact checking stand and in the job casing at the vendor’s shop.
A thin coaling of color transfer material (such as Piussian blue) shall he applied at three locations 120 degrees apan to four or more teeth of the dry degreased gear. With the gear elements hekl lirmly on the correct center distance and with the shall centerlines parallel within 42 pm per m0.5 mils/Ol with a total misahgnmcntofisot more than 25 pmfl mu), the coated teeth shall he rotated through the mesh with a moderate drag torque applied in a direction that vs ill cause the teeth to contact on the normally loaded faces. The color transfer shall show evidence of contact distributed across the face as prescribed by the vendor. Prior to the contact tests, the vendor shall make available to the purchaser a contact drawing or vendor engineering specification that defines Lh expected and acceptable contact. tJnrnodilied tooth profile leads shall show a minimum contact of 70% along the axis and 30% radially. Contact drawing.. or specifications and the results of the contact checks shall be delivered with the unit documentation. The results of the contact check shall he preserved by lifting the colors from a tooth, by applying and peeling off a strip of clear adhesive tape and then sticking the tape to an annotated sheet of paper.
2.7.2.2 Spiral bevel gear-tooth contact shall be checked per Appendix Ci
• 2.7.2.3 The vendor shall have a manufacturing process control system to assure that the designed quality of gearing is pen. duced, ‘The process control system should include: manufacturing planning, machine tool maintenance and inspection programs. gear generating, hardening and finishing pnieedures. cutting tool selection and mainte’ -c procedures, material control piecedurcs, heat treatment control, inspection procedures, and quality as.surancc programs required to achieve and maintain the required gear quality.
If specified, gear elements shall be checked perlS() 1328-I for required gear-tooth accuracy and charts shall he provided.
2.7.2.4 Gear elements shall not be modified on the basis of tooth contact checks made in the gear casing. Gear elements may he modified on the basis of results from gear checking madiines or contact pattern while in the checking stand.
2.7.2.5 The gear vendor shall demonstrate the axial stability of each meshing pair o(doukile.helical gears operating with pinion speeds above I .8(i) r’min by either (a) measuring the unfiltered peak-to-peak shaft axial vibration, which shall nut exceed 60 pm (2.5 mils during full-speed testing. or b using indicators to make a slow rotation check. The preferred method for this slow rotation check is to hold one member wsually the gear wheel) firmly in a fixed axial position and indicate the axial movement of die other member (usually the pinion as the parts are rotated through at least one full revolution of the gear wheel with a drag lonjue applied in a direction that will force the normall loaded tooth faces into contact. The total axial motion of the other member (pinion) relative to the fixed member tgearl shall not exceed 40 p rn 1.5 milsi for gear units having a 20 nis i4J100 ftmin) pitch line velocity or greater and 6Opm (2.5 mik) for gear units having less than a 20 .n1sec (4.()0 ftmin) pitch line velocity.
2.7.3 Shafts
2.7.3.1 Shafts shall be sized to transmit the gear-rated power within the stress limits of ACiMA 64J0lDt)7. Shafts shall he made of one.piece. heat’ireatesi forged, or hot.rolled steel: shall be accurately machined throughout their entire length: and shall be suii• ably tinished at their bearing surfaces.
• 2.7.3.2 If specified. or when vibration ansior axial-position probes arc Furnished, the rotor shaft-sensing areas lo be observed by radial-vibration probes shall he concentric with the bearing journals. All shaft-sensing areas iboth radial vibration and axial positiont shall be free from stencil and scribe marks or any other surface discontinuity, such as an oil hole or a keyway. for a miiiiniurn of one probe-lip diameter on each side of the probe. For gear units with axial floats that exceed half of a probe tip diameter. the probe sensing area shall be long enough to cover the entire float, plus one probe tip diameter on each side. These areas shall not be metallized. sleeved, or plated. The final surface finish shall be a maximum of flit pm(32 pin.).