Stainless Steel Pipe Fittings

Lap Joint Flanges (LJ Flanges) By yaang.com

Written by
Lap Joint Flanges (LJ Flanges) By yaang.com

Lap Joint Flanges (LJ Flanges) are used on piping fitted with lapped pipe or with lap joint stub ends the combined initial cost of the two items being approximately one-third higher than that of comparable welding neck flanges.
Their pressure-holding ability is little, if any, better than that of slip-on flanges and the fatigue life of the assembly is only one-tenth that of welding neck flanges. The lap joint flange with the stub end assembly are normally used in systems requiring frequent dismantling for inspection and cleaning and where the ability to swivel flanges and to align bolt holes materially eases the erection of large diameter or unusually stiff piping. These flanges are also used in applications where there is a need to facilitate bolt alignment. Their use at points where severe bending stress occurs should be avoided.
Lap Joint Flanges (LJ Flanges) or Loose flange(LF flange) called are used on piping fitted with lapped pipe or with lap joint stub ends the combined initial cost of the two items being approximately one-third higher than that of comparable welding neck flanges. Their pressure-holding ability is little, if any, better than that of slip-on flanges and the fatigue life of the assembly is only one-tenth that of welding neck flanges. The lap joint flange with the stub end assembly are normally used in systems requiring frequent dismantling for inspection and cleaning and where the ability to swivel flanges and to align bolt holes materially eases the erection of large diameter or unusually stiff piping. Lap Joint flanges have certain special advantages:Freedom to swivel around the pipe facilitates the lining up of opposing flange bolt holes.Lack of contact with the fluid in the pipe often permits the use of inexpensive carbon steel flanges with corrosion resistant pipe. In systems which erode or corrode quickly, the flanges may be salvaged for re-use.

Dimensions Lap Joint Flanges & Stud Bolts ASME B16.5

  • ANSI B 16.5 Class 150 lb
  • ANSI B 16.5 Class 400 lb
  • ANSI B 16.5 Class 900 lb
  • ANSI B 16.5 Class 300 lb
  • ANSI B 16.5 Class 600 lb
  • ANSI B 16.5 Class 1500 lb

Meterial & Standard for Lap Joint Flanges (LJ Flanges):

CARBON STEEL

ASTM A 105, ASTM A 181
Alloy Steel
ASTM A 182, GR F1, F11, F22, F5, F9, F91

Nickel Alloys
Monel 400 & 500, Inconel 600 & 625, Incolloy 800, 825, Hastelloy C22,C276

Copper Alloys
Copper, Brass & Gunmetal

Size
1/8″ NB TO 48″NB.

Class
150#, 300#,400 #,600#,900#, 1500# & 2500 #.

Standard ANSI
ANSI B16.5, ANSI B16.47, MSS SP44, ANSI B16.36, ANSI B16.48

DIN
DIN2527, DIN2566, DIN2573, DIN2576, DIN2641, DIN2642, DIN2655, DIN2656, DIN2627, DIN2628, DIN2629, DIN 2631, DIN2632, DIN2633, DIN2634, DIN2635, DIN2636, DIN2637, DIN2638, DIN2673

B.S
BS4504 , BS4504, BS1560, BS10

Dimensional Tolerances of Lap Joint Flanges (LJ Flanges) ASME B16.5

Lap joint flange draws

Dimensions are in millimeters unless otherwise indicated.

OUTSIDE DIAMETER

≤ 24 = 1.6 mm
> 24 = ± 3.2 mm

INSIDE DIAMETER

 10 = ± 0.8 mm
 12 = + 1.6 mm / – 0 mm

DIAMETER OF CONTACT FACE

1.6 mm Raised Face = ± 0.8 mm
6.35 mm Raised Face
Tongue & Groove / Male-Female = ± 0.4 mm

DRILLING

Bolt Circle = 1.6 mm
Bolt Hole Spacing = ± 0.8 mm
Eccentricity of Bolt Circle with Respect to Facing
 2½ = 0.8 mm max.
 3 = 1.6 mm max.

DIAMETER OF COUNTERBORE

Same as for Inside Diameter

OUTSIDE DIAMETER OF HUB

 12 = + 2.4 mm / – 1.6 mm
 14 = ± 3.2 mm

THICKNESS

 18 = + 3.2 mm / – 0
 20 = + 4.8 mm / – 0

LENGTH THRU HUB

 18 = + 3.2 mm / – 0.8 mm
 20 = + 4.8 mm / – 1.6 mm

SS Lap Joint Flange CS Lap Joint Flange Alloy Steel Lap Joint Flange F5 Lap Joint Flange
F11 Lap Joint Flange F22 Lap Joint Flange F12 Lap Joint Flange F91 Lap Joint Flange
SS 304 Lap Joint Flange SS 304L Lap Joint Flange SS 316 Lap Joint Flange SS 316 L Lap Joint Flange
SS 317 Lap Joint Flange SS 317L Lap Joint Flange SS 321 Lap Joint Flange SS 347H Lap Joint Flange
SS 904L Lap Joint Flange Duplex Lap Joint Flange Super Duplex Lap Joint Flange S31803 Lap Joint Flange
S32205 Lap Joint Flange Monel 400 Lap Joint Flange Monel K500 Lap Joint Flange Inconel Lap Joint Flange
Duplex Threaded Flange Super Duplex Threaded Flange S32750 Threaded Flange S32760 Lap Joint Flange
F51 Lap Joint Flange F53 Lap Joint Flange A694 F42 Lap Joint Flange A694 F46 Lap Joint Flange
A694 F52 Lap Joint Flange A694 F56 Lap Joint Flange A694 F60 Lap Joint Flange A694 F65 Lap Joint Flange
A694 F70 Lap Joint Flange A350 LF2 Lap Joint Flange A350 LF3 Lap Joint Flange A707 L1 Lap Joint Flange
A707 L2 Lap Joint Flange A707 L3 Lap Joint Flange A105 Lap Joint Flange F904L Lap Joint Flange
Inconel 625 Lap Joint Flange Incoloy 800 Lap Joint Flange Incoloy 800H Lap Joint Flange Incoloy 800HT Lap Joint Flange
Hastelloy Lap Joint Flange Hastelloy B2 Lap Joint Flange Hastelloy B3 Lap Joint Flange Hastelloy C22 Lap Joint Flange
Hastelloy C276 Lap Joint Flange KOC approved Lap Joint Flange KNPC approved Lap Joint Flange AAramco approved Lap Joint Flange

The Lap Joint Flanges (LJ Flanges) are practically identical to a slip-on flange except it has a radius at the intersection of the bore and flange face. This radius is necessary to have the flange accommodate a lap joint stub end. Normally, a lap joint flange and a lap joint stub end are mated together is an assembly system.

Source: Zhejiang Yaang Pipe Industry Co., Limited (www.yaang.com)

Article Categories:
Flange

Leave a Comment

Your email address will not be published. Required fields are marked *