API Recommended Practice 686 - Machinery …

1 StandardEditionSectionInquiry #QuestionReply686 First Edition, February 1996 Chapt. would like to have a confirmation on the material that should be used for the leveling pads to be utilized under the pump baseplate leveling jackscrews. In fact in the grouting checklist, Chapter 5, Section - Mounting Plate Design Verification, stainless steel is indicated as material for the leveling pads. However in Figure G-1 of Chapter 5, carbon steel is indicated the material. We consider that either SS or CS materials could be used. Please jackscrew leveling pads should be constructed of stainless steel as indicated in Chapter 5, Paragraph and as indicated in Section 4, Grouting Checklists, Paragraph , under Mounting Plate Design Verification. The material designation shown in Figure G-1 is incorrectly shown as carbon steel and will be corrected in the next edition of the steel is selected due to the potential for corrosion of carbon steel. After the mounting plate jackscrews are removed when the grout has cured, the jackscrew holes are to be sealed to exclude contamination.

2 Should this barrier seal fail or not be installed water might enter the jackscrew hole and corrosion of carbon steel leveling pads would occur. As the corrosion advances, the carbon steel leveling pad will swell and could result in cracking of the grout and/or delamination of the grout-to-concrete Edition, February 1996 Chapt. to Chapter 6, Section , is it allowable to use T-type strainer for changing the direction at pump suction piping, instead of a long radius elbow? Edition, February 1996 Chapt. have a 12 in. 1500# RTJ flange (with OD of 24 in. and a raised face OD of 15 in.). Chapter 6, Section states that the maximum allowable misalignment is to calculated by the outside diameter of the flange, ( raised face flanges are to be measured at the raised face) up to a maximum of in. What is the maximum allowable measurement at the raised face? Is it in. or in., bearing in mind that the pipe contains 1100 psi water at 280 C?If the outside diameter of the raised face is 15 in.

3 , then the maximum allowable misalignment is in. at the raised face mating surfaces and in. at the outside diameter of the Edition, February 1996 Chapt. is ring heating meant to be applied circumferentially? Is it at a lower, localized heat, "around" the mating piping "flange" to the pump connecting "flange" or to the mating piping or both?Ring heating refers to a circumferential band of heat applied to the piping, not the mating flange, connected to a machine. Typical industry Practice is to apply this heating to the pipe at a sufficient distance from the flanges that heat conduction to the Machinery is negligible. The direct application of heat to the Machinery flange or the mating piping flange is discouraged due to the risk of damage to the internal components of the machine. 686 First Edition, February 1996 Chapt. piping that is attached during ring heating, will there be a piping/flange size restriction?No, there is not a piping flange size restriction. The magnitude of the piping misalignment to be corrected, the piping metallurgy, the pipe wall thickness, the location of pipe supports as well as piping flexibility should be considered when making the decision to apply ring heat or alternative methods to correct pipe strain.

4 686 First Edition, February 1996 Chapt. API 686 1st edition specify the type of gasket that can be used to isolate heat from the pump and piping during ring heating process that will also isolate the pump from stray electric currents from nearby welding?No, RP 686 does not address application of a dual-purpose gasket. The intention of the gasket described in RP 686 paragraph is to help provide electrical isolation of the Machinery from the piping. The intention of the note in Chapter 6, Section , of RP 686 is to provide thermal insulation of the machine from the piping. API Recommended Practice 686 - Machinery Installation and Installation DesignLast update: August 24, 2006 1 of 2 StandardEditionSectionInquiry #QuestionReply686 First Edition, February 1996 Chapt. 4, Section , talks about the vertical distance from the machine centerline to the" base". Is the base the base of the machine( bottom of bedplate etc) or the bottom base of the foundation mass in the ground?The vertical distance in the note following paragraph refers to the distance from the centerline of the machine to the bottom of the foundation mass in the Edition, February 1996 Chapt.

5 Reference to Chapter 4, Section , "adhesive stud bolt with nut and washer", is it true that the nut and washer go on top of the anchor to hold down the baseplate? 2 of 2