Does MSS SP-97 olet sizing replace ASME B31.3 branch reinforcement?

No. Integrally reinforced fittings still need project confirmation against Para. 304.3. Use this chart for envelope / cutout dimensions, then run Pipe Branch Reinforcement when area replacement is required.

Why does run size show Fail for a size-on-size branch?

Reducing-olet screening rows often start the run band above the outlet NPS. Size-on-size cradles can differ — confirm the OEM chart before ordering.

Where do Threadolet thread sizes come from?

End-prep notes list NPT matching the outlet NPS (e.g. NPS 1 → NPT 1 in) for Class 3000 / 6000 Threadolet screening.

Olet Fitting Dimensions & Branch Sizing (Weldolet / Sockolet / Threadolet) — Threadolet 4×1 Class 3000 (imperial)

Parameter	Value
Material	A105

Engineering Reference & ASME Code Basis

1. Core Formula & Variable Definitions

MSS SP-97 (Integrally Reinforced Forged Branch Outlet Fittings) · ASME B31.3 (2022 Edition) · Para. 304.1.2 / 304.3.2 (branch design thickness & area replacement — screening note) · ASME B36.10M (matching Weldolet schedule OD / wall) · ASTM A105 / A182 (forging material families)

D_run,min ≤ D_run ≤ D_run,max · MSS SP-97 consolidated run size

t_b = P · D_ob2(S E W + P Y) · ASME B31.3 §304.1.2 screening

MSS SP-97 Weldolet / Sockolet / Threadolet envelope dimensions (A, B, d_hole, J)

Standard MSS SP-97Hero Height ARun match D_run,min…maxt_b screen B31.3 §304.1.2

Envelope dimensions A (height), B (base diameter), d_hole (header cutout), branch bore, and Sockolet socket depth J are taken from MSS SP-97 / Bonney Forge-style published charts by olet type and outlet rating. Weldolet uses schedule families (STD / XS / Sch 160); Sockolet and Threadolet use Class 3000 / 6000. Run NPS must fall inside the consolidated run-size band for Pass. Optional t_b uses B31.3 §304.1.2 with screening S for A105 (138 MPa) or A182 F316 (115 MPa), E = W = 1, Y = 0.4. Does not replace §304.3.2 area replacement.

A (Outlet Height) — Vertical envelope from run OD to olet top / face (mm or in) — hero output.
B (Base Diameter) — Outside diameter of the olet reinforcement base at the header (mm or in).
d_hole (Header Cutout Diameter) — Recommended hole diameter in the run pipe for olet installation (mm or in).
J (Socket Depth) — Sockolet socket engagement depth (mm or in). Not used on Weldolet / Threadolet.
D_ob (Outlet Outside Diameter) — Branch pipe OD from B36.10M (Weldolet schedule) or screening OD for forged class outlets.
t_b (Branch Design Thickness) — B31.3 §304.1.2 screening thickness for the outlet; export only — pad area is separate.

2. MSS SP-97 Lookup Rules & Scope

Field screening envelopes only. Confirm the current manufacturer dimensional chart and B31.3 reinforcement before purchase or fabrication.

Weldolet rating basisSTD / XS / Sch 160

Butt-weld olet ends match pipe schedule wall. STD ≈ Sch 40; XS ≈ Sch 80 for common carbon-steel sizes.

Sockolet / Threadolet ratingClass 3000 / 6000

Forged pressure-class outlets (MSS SP-97 / B16.11 family). Socket depth J applies to Sockolet only.

Consolidated run sizePass / Fail

Selected header NPS must lie between published runMin and runMax for that outlet. Outside range → Fail screening.

Out of scope§304.3.2 area replacement

Pad / excess area A1–A5 checks remain in the Pipe Branch Reinforcement calculator.

Quick Reference Lookup Table

MSS SP-97 olet screening chart (selected outlets) — matches this app
Type	Run × Outlet	Rating	A	B	Note
Weldolet	6 × 2	STD	38.1 mm	58.7 mm	Default duty
Sockolet	8 × 1.5	3000	33.3 mm	J = 12.7 mm	Socket depth
Weldolet	12 × 4	XS	2.25 in	4.88 in	Imperial
Threadolet	4 × 1	3000	1.31 in	NPT 1 in	Threaded
Weldolet	6 × 3	STD	44.5 mm	84.1 mm	Larger outlet
Sockolet	6 × 2	3000	38.1 mm	J = 15.7 mm	Class 3000
Weldolet	8 × 2	XS	42.9 mm	65.1 mm	XS family
Threadolet	6 × 1.5	3000	33.3 mm	NPT 1½ in	Threaded

A / B from MSS SP-97 screening rows in this app. Confirm OEM chart; integrally reinforced fittings may still need B31.3 area checks on large/high-pressure duties.

3. Applicability & Fitting / Material Limits

Use for MSS SP-97 forged olet envelope lookup. Not a substitute for OEM charts, size-on-size specials, or formal reinforcement calculations.

Group / Regime	Range / Condition	Limit / Criterion	Engineering Notes
Weldolet (BW)	—	—	Schedule-rated BW branch outlets. Default duty: NPS 6 run × NPS 2 STD on A105.
Sockolet (SW)	—	—	Class 3000 / 6000 socket-weld outlets with published socket depth J.
Threadolet (NPT)	—	—	Class 3000 / 6000 threaded outlets. End prep lists NPT size matching the outlet NPS.
A105 / A182 F316	Screening S at entered T context	A105 138 MPa · F316 115 MPa	Forging material presets for t_b screening only — confirm Table A-1 / forging allowable at metal design temperature.

Code Applicability & Safety Boundaries

Does not certify MSS SP-97 manufacturing tolerances or OEM weight.
Does not perform ASME B31.3 Para. 304.3.2 area replacement.
Size-on-size and special run cradles may differ from reducing consolidated ranges.

4. Step-by-Step Worked Example

Field VerificationShow

Worked Example — Weldolet 6×2 STD (metric)

Look up a carbon-steel Weldolet on an NPS 6 header with an NPS 2 STD outlet for layout and cutout planning.

Olet type:WeldoletRun × Outlet:NPS 6 × NPS 2Rating:STDMaterial:A105Design P / T:2.0 MPa · 150 °C

Select MSS SP-97 row

Weldolet · STD · outlet NPS 2

Result:A = 1.50 in = 38.1 mm · B = 2.3125 in ≈ 58.7 mm

Check consolidated run size

runMin = 2.5 · runMax = 36 · run = 6

Result:Pass

Read cutout and bore

d_hole and branch ID from the same row

Result:Use d_hole for header prep; bore ≈ STD ID family

Optional t_b screen

Formula: t_b = P D_ob / (2(SE + PY))

P = 2 MPa · D_ob from Sch 40 · S = 138 MPa · Y = 0.4

Result:Export t_b for wall context — still run pad area check if required

Conclusion: Hero height A = 38.1 mm with base B ≈ 58.7 mm and Pass run match. Next: verify reinforcement in Pipe Branch Reinforcement if the duty is not exempt.

5. How to look up MSS SP-97 olet dimensions

1
Choose olet type and rating
Weldolet → STD / XS / Sch 160. Sockolet or Threadolet → Class 3000 / 6000.
2
Enter run and outlet NPS
Header (run) size and branch outlet size. Confirm Pass on the consolidated run-size band.
3
Read A, B, d_hole (and J)
Hero shows height A. Rows list cutout, base diameter, bore, and Sockolet socket depth when applicable.
4
Carry to reinforcement if needed
High-pressure or large outlets: open Pipe Branch Reinforcement with the same run / branch NPS.

6. Frequently Asked Questions & Technical References

Show

Weldolet ends are butt-weld and sized by pipe schedule (STD / XS / 160). Sockolet is a socket-weld forging sized by pressure class (3000 / 6000) with a published socket depth J.