B73.1M is a dimensional contract, not a performance one.
ASME/ANSI B73.1M specifies the envelope of a horizontal end-suction centrifugal process pump: the centreline height, the foot-mounting pattern, the suction and discharge flange sizes and their positions, the shaft extension, and the baseplate. Pumps carrying the same ANSI designation share those dimensions.
What that buys you
- A pump of the same designation drops onto the existing baseplate and foundation bolts.
- Suction and discharge flanges land where the existing piping already is — no re-piping, no spool pieces.
- Shaft centreline height matches, so the existing coupling and motor alignment survive.
- One spare-parts programme covers a mixed fleet within a frame group. This is the reason the 8896 is specified as “maximum interchangeability, minimum spare parts inventory.”
What it does not
- B73.1M says nothing about hydraulic performance. Two pumps of the same designation can have very different curves, efficiencies and NPSHr.
- It does not standardise internal parts — impellers, wear rings, seal chambers and bearings are the manufacturer’s design.
- It does not standardise metallurgy or seal chamber geometry, which is where most process problems actually live.
Which is why a like-for-like swap should always be confirmed against the duty point, not just the flange pattern. Send us the tag data and we will check it.
8896 designations, frame by frame.
Fourteen ANSI designations across three power frames, covering 31 hydraulic sizes. Find the designation on your existing pump’s nameplate or data sheet, and the row below tells you which 8896 shares its envelope.
| ANSI Designation | 8896 Frame | Hydraulic Size(s) | Discharge | Suction |
|---|---|---|---|---|
| AA | ST1 | 1 x 1½-6 · 1 x 1½-8 | 1" | 1½" |
| AB | ST1 | 1½ x 3-6 · 1½ x 3-8 | 1½" | 3" |
| A05 | MT1/LT1 | 1 x 2-10 | 1" | 2" |
| A20 | MT1/LT1 | 1½ x 3-13 | 1½" | 3" |
| A30 | MT1/LT1 | 2 x 3-13 | 2" | 3" |
| A40 | MT1/LT1 | 3 x 4-10H · 3 x 4-13 | 3" | 4" |
| A50 | MT1/LT1 | 1½ x 3-10 | 1½" | 3" |
| A60 | MT1/LT1 | 2 x 3-8 · 2 x 3-10 | 2" | 3" |
| A70 | MT1/LT1 | 3 x 4-8 · 3 x 4-8G · 3 x 4-10 | 3" | 4" |
| A80 | MT1/LT1 | 4 x 6-10G · 4 x 6-10H · 4 x 6-13 | 4" | 6" |
| A90 | XLT1 | 6 x 8-13 | 6" | 8" |
| A100 | XLT1 | 8 x 10-13 | 8" | 10" |
| A110 | XLT1 | 6 x 8-15 | 6" | 6" |
| A120 | XLT1 | 8 x 10-15 · 8 x 10-15G | 8" | 10" |
Discharge and suction are nominal flange sizes in inches. Full dimensional data — X, A, B, D, SP, shaft and keyway — is on the 8896 product page.
Three power ends.
Small Frame
Designations AA and AB. Six hydraulic sizes from 1 x 1½-6 to 1½ x 3-8. Shaft 0.875″, keyway 3/16 × 3/16, centreline height 4″ (102 mm).
Medium & Large Frame
Designations A05 through A80. Sixteen hydraulic sizes from 2 x 3-8 to 4 x 6-13. Shaft 1.125″ (MT1) or 1.875″ (LT1), centreline height 4″ (102 mm).
Extra-Large Frame
Designations A90 through A120 plus the 16H and 17 hydraulics. Nine sizes from 6 x 8-13 to 8 x 10-17. Shaft 2.375″, keyway 5/8 × 5/8, centreline height 6″ (152 mm).
The 8830 Series drops into a Durco Mark III footprint.
B73.1M fixes the mounting envelope, but it says nothing about the parts inside the pump. The Pinnacle 8830 Series goes further than the standard requires: the 8831 and 8832 are 100% interchangeable with Durco Mark III® Groups 1 and 2.
Send us four numbers and a nameplate.
Flow, head, fluid and temperature — plus a photo of the existing pump’s nameplate. We will confirm the designation, check the duty against the 8896 curve, and tell you plainly if the hydraulics do not suit, rather than selling you a pump that fits the baseplate and nothing else.