Frost-Free Sillcock Length by Wall Thickness: Woodford, Prier and Sioux Chief Stock Sizes, Inlets and Why the Old One Split
Woodford 17, 19, 27 and Prier C-144 ship in wall thicknesses from 4 to 24 inches in 2 inch steps; Sioux Chief stops at 12. Order by wall, not overall length.
- Verified
- Updated
- 8 min read
- 7 sources
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Short answer
A frost-free sillcock is ordered by wall thickness, not by the overall length of the faucet it replaces. Woodford’s Model 17, 19 and 27 spec sheets list wall thicknesses of 4 to 24 inches in 2 inch steps and define overall length as wall thickness plus the inlet fitting, so a 4 inch Model 17 valve stem is 5 7/8 inches long. Prier’s C-144 ships from stock from close-coupled to 24 inches of insertion, and Sioux Chief’s 118 and 119 series stop at 12 inches. Measure from the outside face of the siding to the point inside the heated space where the supply pipe will connect, then order that size: Woodford’s Model 19 sheet requires the inlet connection to sit in a heated area, pitched slightly down toward the nozzle. Woodford 17 and 19 and Prier C-144 are ASSE 1019 listed and rated to 125 psi. A hose left attached in a freeze is the one failure every maker names.
The picks
A 4 inch wall with a threaded stub, no soldering
Woodford 17P-4-MH, 4 inch wall, P inlet
Woodford's P inlet is a combination 1/2 inch female pipe thread and 3/4 inch male pipe thread; ASSE 1019 Type C listed, 125 psi and 120 F maximum, per Form No. 17.114
Anyone who has already lost a sillcock to a forgotten hose
Woodford 19CP-12, 12 inch wall, CP inlet
Same 4 to 24 inch range as the Model 17 plus the patented resetting pressure relief valve; CP inlet is a combination 1/2 inch male pipe thread and 1/2 inch female sweat, per Form No. 19.114
A 4 inch wall where the flange must carry the drainage pitch
Prier C-144D04, 4 inch insertion, D inlet
D style inlet is 1/2 inch MPT by 1/2 inch SWT; ASSE 1019, 125 psi and 140 F, integral cast flange with built-in drainage pitch, per form C-144-Y
A 10 inch wall and no torch or crimp tool
SharkBite 24629LF, 10 inch, push-to-connect
Listing title states 1/2 inch push-to-connect by 3/4 inch MHT, for PEX, copper, CPVC, PE-RT and HDPE; SharkBite's own spec sheet was not opened this session, so no standard is attributed
Every sillcock on the house, after the hose is off
Frost King FC1 foam faucet cover, 4-pack
Water-resistant oval foam cover, four per pack; a cover does not replace hose removal, which every maker sheet on this page requires
If the old faucet split, the number printed on its box is the last one to copy: a sillcock that burst may have been too short to put its valve in heated space in the first place.
Which length fits your wall?
Woodford orders by “wall thickness” and Prier by “insertion”; both mean the buried part, from the back of the flange to the inlet.
| Maker and model | Stock sizes (inches) | How the sheet defines length | Sheet |
|---|---|---|---|
| Woodford Model 17 | 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24 | Overall length = wall thickness + inlet option length; valve stem is wall thickness + 1 7/8 in | Form 17.114 |
| Woodford Model 19 | 4 to 24 in 2 in steps | Same formula; the sheet adds that the inlet must be in a heated area | Form 19.114 |
| Woodford Model 27 | 4 to 24 in 2 in steps | Same formula; operating rod overall length is wall thickness + 4 in | Form 27.108 |
| Prier C-144 | Super close-coupled, close-coupled, 4 to 24 in 2 in steps, special sizes on request | Ordered by insertion length | C-144-Y |
| Prier C-634 (commercial) | 4 to 24 in 2 in steps | Ordered by insertion length; mounts through a 1 3/8 in round opening | C-634-W |
| Sioux Chief 118 and 119 | 4, 6, 8, 10, 12 | Length listed per part number | Class listing 123 |
Woodford’s rough-in drawing carries the instruction in five words: “specify model, inlet and wall thickness.” Measure the wall you have, from the outside face of the finish to the inside face where the supply will land, and pick that row. The tape decides, not the framing size, because siding, sheathing and interior finish all add to it.
Three names in the brief have no row. No current Mansfield spec sheet was found, and Prier’s own C-144 sheet mentions Mansfield only as a past hydrant style its C-144KT-806 universal vacuum breaker kit fits. Moen and Everbilt pages would not load this session, so their lengths are unverified rather than absent.
Which inlet matches your pipe?
The inlet code is the second half of the part number and it has to match the pipe already in the wall.
| Connection | Woodford 17, 19, 27 codes | Prier C-144 codes | Sioux Chief |
|---|---|---|---|
| 1/2 in copper sweat | C (combination 1/2 in inside, 3/4 in M outside), CP (1/2 in female sweat side), CM (compression and sweat) | D (1/2 in MPT x 1/2 in SWT) | 118M and 118W series list 1/2 in MIP/FSWT |
| 3/4 in copper sweat | C3 | F (3/4 in SWT) | Not listed |
| Threaded, MIP or FIP | CP (1/2 in male pipe thread side), P (1/2 in female pipe thread x 3/4 in male pipe thread) | T (3/4 in MPT x 1/2 in FPT) | 119 series, 1/2 in MIP |
| PEX crimp, ASTM F1807 | PX (1/2 in), PX3 (3/4 in) | X (1/2 in crimp), FX (3/4 in crimp) | 118X and 119X, 1/2 in F1807 |
| PEX expansion, F1960 or Wirsbo | W (1/2 in Wirsbo), W3 (3/4 in Wirsbo), R (1/2 in Rehau) | W (1/2 in Wirsbo), FW (3/4 in Wirsbo) | 118W, 1/2 in F1960 |
| Push-fit or press | Not listed | G (1/2 in SharkBite push-fit), Y (1/2 in press-fit) | 119Q, 1/2 in push fit |
| CPVC | Not listed | C (1/2 in CPVC glue-in) | 118-C and 119-C, 1/2 in CPVC |
Woodford’s Model 27 sheet shows only the C, CP, CP3, P, PX and PX3 inlets, so an expansion PEX supply (Wirsbo or Rehau) narrows the Woodford choice to the 17 or 19. The SharkBite 24629LF is the no-tool route: its listing states a 1/2 inch push-to-connect inlet for PEX, copper, CPVC, PE-RT and HDPE.
Which one has the backflow device built in?
| Model | Backflow protection printed on the sheet | Rating |
|---|---|---|
| Woodford 17 | Integral device to 125 psi backpressure, ASSE 1019 Type C listed, no add-on vacuum breaker needed | 125 psi, 120 F |
| Woodford 19 | Same integral device and ASSE 1019 Type C listing | 125 psi, 120 F |
| Woodford 27 | Separate Model 50HA, ASSE 1052 approved, IAPMO listed, two independent check valves, replace every 3 to 5 years | 125 psi, 120 F |
| Prier C-144 | Anti-siphon vacuum breaker and backflow check valve, “per ASSE 1019” | 125 psi, 140 F |
| Prier C-634 | Integral vacuum breaker with two check valves, field testable per ASSE 1052 | 125 psi, 140 F, 16 gpm at 25 psi differential |
| Sioux Chief 118X, 119X | Marked anti-siphon; no standard number on the listing | Not printed on the listing |
Both Woodford and Prier print the same limit on their ASSE 1019 models: do not leave the faucet under more than 12 continuous hours of water pressure. A timer left running on a drip line breaks that rule.
Why did the old one split?
Woodford’s own explanation, in capitals on its how-it-works sheet: the only possible cause of a burst tube is an obstruction such as a hose left on in freezing conditions, or an installation that prevents the water draining after shut-off.
The mechanism is simple. The valve closes several inches inside the house, and the tube in front of it should empty through the nozzle. A hose traps that water. It freezes from the outside inward, the closed valve leaves the ice nowhere to expand, and the copper splits downstream of the valve, where nothing leaks until spring.
Slope is the other half. Woodford’s Model 17 warning reads that the faucet “must be installed with downward pitch toward nozzle and hose must be removed in freezing weather or faucet may freeze and burst.” Prier casts the drainage pitch into the C-144 flange. Woodford’s Model 19 sheet adds two more requirements: seal the gap between house and faucet against air leaks, and insulate around the faucet, wall board and sill plate.
Two designs are built for the forgotten hose. The Model 19’s patented resetting pressure relief valve, per its sheet, prevents the tube bursting even if a hose is unintentionally left on. The Model 27 drains as the handle is shut off even with the hose attached, provided the handle is turned clockwise until seated and water runs from the drain hole.
Measure twice, then cover it
Do not order until the tape has been through the wall. If the old faucet froze, the Woodford 19CP-12 is the one whose spec sheet claims to survive the next forgotten hose, and only in a 12 inch wall. A Frost King foam cover keeps wind off the nozzle but makes no heat, and it does nothing for a hose left under it. Why the burst is rarely where the ice is: the frozen pipes guide.
Frequently asked questions
How do I measure for a frost-free sillcock?
Measure the wall, not the old faucet. Woodford's rough-in drawing labels the ordered dimension wall thickness and defines overall length as wall thickness plus the inlet option length, so the box number is the buried part only. Measure from the outside face of the siding to where the supply pipe will connect inside, and Woodford's Model 19 sheet requires that inlet to sit in a heated area.
What lengths do frost-free sillcocks come in?
Woodford's Model 17, 19 and 27 sheets all list wall thicknesses of 4, 6, 8, 10, 12, 14, 16, 18, 20, 22 and 24 inches. Prier's C-144 adds super close-coupled and close-coupled below 4 inches and a special-size code above 24. Sioux Chief's 118 and 119 series are listed in 4, 6, 8, 10 and 12 inches only, so a thick wall rules them out.
Do I still need a vacuum breaker on an anti-siphon sillcock?
Not on the models that print an integral one. Woodford's Model 17 and 19 sheets state each contains an integral backflow device protecting up to 125 psi of backpressure and therefore does not require an add-on vacuum breaker, listed to ASSE 1019 Type C. Prier prints ASSE 1019 for the C-144. Woodford's Model 27 uses a separate Model 50HA preventer instead, ASSE 1052 approved and IAPMO listed.
Why did my frost-free faucet burst even though it is frost-free?
Woodford's own explanation names one cause: an obstruction such as a hose left on in freezing weather, or an installation that stops the tube draining after shut-off. Trapped water freezes from the outside inward, and with the valve closed the expanding ice has no relief, so the copper tube splits. The leak shows only when the water is turned back on in spring.
Which frost-free sillcock survives a hose left on?
Two designs claim it on their spec sheets. Woodford's Model 19 has a patented resetting pressure relief valve that the sheet says prevents the faucet tube from bursting in freezing conditions even if a hose is unintentionally left on. Woodford's Model 27 and Prier's commercial C-634 are described as draining even with the hose attached. The Model 17 and Prier C-144 are not.
Fact sheet and how to cite this page
- Answer
- A frost-free sillcock is ordered by wall thickness. Woodford’s Model 17, 19 and 27 spec sheets list 4 to 24 inches in 2 inch steps and define overall length as wall thickness plus the inlet fitting, so a 4 inch Model 17 stem is 5 7/8 inches long. Prier’s C-144 ships from close-coupled to 24 inches; Sioux Chief’s 118 and 119 series stop at 12 inches.
- Applies to
- Woodford 17, 19, 27
- Prier C-144, C-634
- Sioux Chief 118, 119
- Compatibility basis
- Woodford spec sheets Form No. 17.114 (Rev. 04/21), 19.114 (Rev. 10/23) and 27.108 (Rev. 03/25); Woodford’s How a Standard Frost-Proof Faucet Works sheet (Form No. works.104); Prier spec sheets C-144-Y and C-634-W; the Sioux Chief sillcock and hydrant product class listing
- Assumptions
- Woodford orders by wall thickness and Prier by insertion length; both are the buried dimension, not the overall length, and the page treats them as the same measurement.
- No current Mansfield spec sheet was found; Prier’s C-144 sheet mentions Mansfield only as a past hydrant style its universal vacuum breaker kit fits. Moen and Everbilt pages were not readable this session, so none of the three has a row.
- ASSE 1019 is attributed only to Woodford 17 and 19 and Prier C-144, which print it. Sioux Chief’s listing marks its X models anti-siphon without a standard number.
- Method
- Stock lengths, inlet codes, standards, pressure and temperature ratings and installation warnings copied from each maker’s current spec sheet or product listing. OwnerSpec installed nothing and measured no wall.
- Primary source
- Woodford Manufacturing, Freezeless Anti-Siphon Wall Faucet Model 17 spec sheet, Form No. 17.114, Rev. 04/21 (PDF) (manufacturer or vendor document)
- Facts verified
- Last updated
- Cite as
- OwnerSpec, "Frost-Free Sillcock Length by Wall Thickness: Woodford, Prier and Sioux Chief Stock Sizes, Inlets and Why the Old One Split", https://ownerspec.com/plumbing/parts/frost-free-sillcock-length-by-wall-thickness/, facts verified 27 September 2026.
Every figure above also appears, with its source, in the article. All sources ยท How OwnerSpec verifies numbers
Sources
- Woodford Manufacturing, Freezeless Anti-Siphon Wall Faucet Model 17 spec sheet, Form No. 17.114, Rev. 04/21 (PDF) (manufacturer or vendor document)
- Woodford Manufacturing, Freezeless Anti-Siphon Wall Faucet Model 19 spec sheet, Form No. 19.114, Rev. 10/23 (PDF) (manufacturer or vendor document)
- Woodford Manufacturing, Backflow Protected Automatic Draining Freezeless Wall Faucet Model 27 spec sheet, Form No. 27.108, Rev. 03/25 (PDF) (manufacturer or vendor document)
- Woodford Manufacturing, How a Standard Frost-Proof Faucet Works, Form No. works.104, Rev. 04/15 (PDF) (manufacturer or vendor document)
- Prier Products, C-144/244 Series Freezeless Wall Hydrant spec sheet, form C-144-Y (PDF) (manufacturer or vendor document)
- Prier Products, C-634 Heavy Commercial Wall Hydrant spec sheet, form C-634-W (PDF) (manufacturer or vendor document)
- Sioux Chief, Sillcocks and Hydrants product class listing (118 and 119 series lengths and inlets) (manufacturer or vendor document)