NFPA Mounting Flanges & Shafts for Hydraulic Pumps & Motors

FLUID POWER - Design Data Sheet 76

For many years the only standardization on pump and motor shafts and mounting flanges had been the SAE (Society of Automotive Engineers) Standard J744a. It was widely accepted by other industries as well as the automotive and is still a valid standard. The NFPA (National Fluid Power Association) started work in 1962 on a set of standards which would more directly apply to industrial fluid power pumps and motors, and would be more complete. This set of standards was unanimously approved by the NFPA Board of Directors and issued in 1965 as NFPA Recommended Standard T3.9.65.1. In 1966 it was also adopted by the ANSI (American National Standards Institute) and issued as B93.6-1966. It has since been revised and now carries the numbers ANSI B93.6-1972 and NFPA T3.9.2 R1. Copies are available from the NFPA.

The purpose of the standard is to encourage manufacturers to use interchangeable dimensions on both mounting flanges and shafts as far as possible to simplify dimensional interchangeability. No standards presently exist for foot mounting dimensions. No performance specifications exist although recommended methods of testing pumps and motors and the manner of presenting test data are given in NFPA Recommended Standard T3.9.17-1971.

The new NFPA and ANSI standards are similar to the SAE standards but differ in these respects: Additional shaft diameters and an alternative long length shaft have been added to the straight-shaft-without-thread listings. Additional mounting flange sizes have been added to provide a wider selection for the designer. NFPA has not assigned any horsepower ratings, making it the responsibility of the pump designer. However, the SAE horsepower ratings are shown for mounting flanges.

STRAIGHT SHAFT (WITHOUT THREADS)
ANSI
Shaft
Code
Shaft
Diam.
Inches
Short
Shaft
Length
Inches
Long
Shaft
Length
Inches
Key
Width
Inches
SAE
Shaft
Code
 Illustration 76_1A (2)
13-1 0.500 0.750 - - - - 0.125 A-A
16-1 0.625 0.938 2.000 0.156 A
22-1 0.875 1.312 2.500 0.250 B
25-1 1.000 1.500 2.750 0.250 B-B
31-1 1.250 1.875 3.000 0.312 C
38-1 1.500 2.125 3.250 0.375 C-C
44-1 1.750 2.625 3.625 0.437 D, E

 

30° INVOLUTE SPLINE
ANSI
Shaft
Code
Shaft
Diam.
Inches
Shaft
Length
Inches
Spline
Specifications
SAE
Shaft
Code
 Illustration 76_1B
13-4 0.500 0.750 9T, 20/40 DP A-A
16-4 0.625 0.938 9T, 16/32 DP A
22-4 0.875 1.312 13T, 16/32 DP B
25-4 1.000 1.500 15T, 16/32 DP B-B
32-4 1.250 1.875 14T, 12/24 DP
38-4 1.500 2.125 17T, 12/24 DP C-C
44-4 1.750 2.625 13T, 8/16 DP D, E
50-4 2.000 3.125 15T, 8/16 DP F

 

STRAIGHT SHAFT (WITH THREADS)
ANSI
Shaft
Code
Shaft
Diam.
Inches
Straight
Shaft
Inches
Thread
Size
Thread
Length
Inches
Key
Width
Inches
 Illustration 76_1C
13-2 0.500 0.750 3/8 - 24 0.532 0.125
16-2 0.625 0.938 1/2 - 20 0.719 0.156
22-2 0.875 1.312 5/8 - 18 0.906 0.250
25-2 1.000  1.500 3/4 - 16 1.062 0.250 
32-2 1.250 1.875 1 - 12 1.219 0.312
38-2 1.500 2.125 1-1/8 - 12 1.375 0.375
44-2 1.750 2.625 1-1/4 - 12 1.562 0.437

 

TAPERED SHAFT WITH THREADS
 ANSI
Shaft
Code
 Shaft Diam.
Inches
Tapered
Shaft
Length
Inches
Threaded
Shaft
Length
Inches
Thread
Size
Key
Width
Inches
 Illustration 76_2A
13-3 0.500 0.688 0.500 5/16-32 0.125
16-3 0.625 0.688 0.719 1/2-20 0.156
22-3 0.875 1.125 0.906 5/8-18 0.250
25-3 1.000 1.375 1.062 3/4-16 0.250
32-3 1.250 1.375 1.219 1-12 0.312
38-3 1.500 1.875 1.375 1-1/8-12 0.375
44-3 1.750 2.125 1.562 1-1/4-12 0.437
50-3 2.000 2.875 1.562 1-1/4-12 0.500

 

MOUNTING FLANGE (TWO-BOLT)
ANSI
Flange
Code
SAE
No.
SAE
HP
Rating
Mount.
Bolt
Circle
Inches
 Mount.
Hole
Diam.
Inches
Pilot
Diam.
Inches
 Illustration 76_2B
50-2 A-A 5 3.250 0.406 2.00
82-2 A 10 4.188 0.438 3.25
101-2 B 25 5.750 0.562 4.00
127-2 C 50 7.125 0.688 5.00
152-2 D 100 9.000 0.812 6.00
165-2 E 200 12.500 1.062 6.50
177-2 F 300 13.781 1.062 7.00

 

MOUNTING FLANGE (FOUR-BOLT)
ANSI
Flange
Code
SAE
No.
SAE
HP
Rating
Mount.
Bolt
Circle
Inches
Mount.
Hole
Diam.
Inches
Pilot
Diam.
Inches
 Illustration 76_2C
101-4 B 25 5.000 0.5625 4.00
127-4 C 50 6.375 0.5625 5.00
152-4 D 100 9.000 0.8125 6.00
165-4 E 200 12.500 0.8125 6.50
177-4 F 300 13.780 1.0625 7.00

 

HYDRAULIC FLANGES FOR SAE PORTS

Standard (Low Pressure) Connection Flanges
Connects dryseal (NPTF) pipe threads, through an O-ring seal, to a mounting surface with rectangular bolt spacing.

Nominal
Size
Inches
Rated
PSI
Dim. A,
Inches
Dim. B,
Inches
Mounting
Bolt Size
O-Ring
Size
3/4 5,000 1.875 0.875 3/8-16 × 1-1/2 -214
1 5,000 2.062 1.031 3/8-16 × 1-3/4 -219
1-1/4 4,000 2.312 1.188 7/16-14 × 1-3/4 -222
1-1/2 3,000 2.750 1.406 1/2-13 × 2 -225
2 3,000 3.062 1.688 1/2-13 × 2 -228
2-1/2 2,500 3.500 2.000 1/2-13 × 2-1/2 -232
3 2,000 4.188 2.438 5/8-11 × 2-3/4 -237

 

High Pressure (6,000 PSI) Connection Flanges
Connects welded pipe through O-ring seal to a 4-bolt mounting surface or to another flange to make a union.

Nominal Size
Inches
Dim. A,
Inches
Dim. B,
Inches
Mounting
Bolt Size
Pipe O.D.
Inches
3/4  2.000 0.937 3/8-16 × 1-1/2 1.063
1 2.250 1.093 7/16-14 × 1-3/4 1.328
1-1/4 2.625 1.250 1/2-13 × 2-1/4 1.672
1-1/2 3.125 1.437 5/8-11 × 2-3/4 1.923
2 3.812 1.750 3/4-10 × 3 2.406
2-1/2 4.875 2.312 7/8-9 × 3-1/2 2.906
3 6.000 2.812 1-1/8-7 × 4-1/2 3.547

 

Rectangular, 4-bolt connection flanges for pumps, motors, valves, and other components. Per SAE J518.

Illustration 76_3 (1) Photo 76_Anchor NPTF Thread Pipe Flange _A (1)

 

Download a PDF of Fluid Power Design Data Sheet 76 - NFPA Mounting Flanges and Shafts for Hydraulic Pumps and Motors

© 1990 by Womack Machine Supply Co. This company assumes no liability for errors in data nor in safe and/or satisfactory operation of equipment designed from this information.

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