Lap Joint Flange Definition and Details
Lap Joint Flanges have all the same common dimensions as any other flange named on this page however it does not have a raised face, they used in conjunction with a “Lap Joint Stub End“.These flanges are nearly identical to a Slip On flange with the exception of a radius at the intersection of the flange face and the bore to accommodate the flanged portion of the Stub End.
Their pressure-holding ability is little, if any, better than that of Slip On flanges and the fatigue life for the assembly is only one tenth that of Welding Neck flanges.They may be used at all pressures and are available in a full size range. These flanges slip over the pipe, and are not welded or otherwise fastened to it. Bolting pressure is transmitted to the gasket by the pressure of the flange against the back of the pipe lap (Stub End).
Lap Joint Flange Standards:
ASME B16.5 Pipe Flanges and Flanged Fittings
ASME B16.47 Series A Steel Flanges NPS 26 Through NPS 60
API 605/ASME B16.47 Series B Steel Flanges NPS 26 Through NPS 60
BS EN 1759 Flanges and their joints. Circular flanges for pipes, valves, fittings and accessories, class-designated. Steel flanges
EN 1092 Circular flanges for pipes, valves, fittings
BS 4504 Circular flanges for pipes,valves and fittings
JIS B2220 Steel pipe flanges
DIN 2641 PN6 Loose (Lapped Joint) Flange Plain Collar
DIN 2642 PN10 Loose (Lapped Joint) Flange Plain Collar
DIN2655 PN25 Loose (Lapped Joint) Flange Plain Collar
DIN2656 PN40 Loose (Lapped Joint) Flange Plain Collar
GOST 12822 Steel loose flanges with welded ring for Pnom from 0,1 to 2,5 MPa (from 1 to 25 kgf/cm<(hoch)2>). Design and dimensions
Hebei haihao group, as a first class manufacturer of Lap Joint flange(LJ flange) /Loose Flange in China,supplys a variety of steel flanges to satisfy our customers’ specifica requirements,which include different size,different schedule,different pressure and different finish faces. Our products are produced strictly according to the required standard. Our raw material for Lap Joint flanges(LJ flange) Loose Flanges all are purchased from big steel companies which can make sure the material in a high quality.