Get the Right HDPE Pipe and Fittings — the First Time
Order the wrong pipe diameter or the wrong Philmac fitting and you’re not just out the return shipping — you’re out the day. This guide gets you to the right SDR rating, the right size, and the right fittings before you check out, not after the truck’s already loaded.
Still have questions? Contact our team — we’re here to help you design the right water system for your operation.
Do You Have IPS-OD or CTS-OD Pipe?
Before you order fittings, it’s worth a 30-second check — this is the single most common mix-up we see, and ordering the wrong standard means paying for shipping twice.
| Standard | Full Name | Common Use | Notes |
|---|---|---|---|
| IPS-OD | Iron Pipe Size — Outside Diameter | Agricultural, ranch, and rural water systems | Most common for farm/ranch HDPE pipe. Philmac IPS-OD fittings are designed for this standard. |
| CTS-OD | Copper Tube Size — Outside Diameter | Residential plumbing, PEX systems | Smaller OD than IPS for the same nominal size. Requires CTS-OD specific fittings. |
All HDPE pipe we carry is IPS-OD unless otherwise noted — so if you’re buying from us, that part’s already decided for you.
Matching existing pipe? Check the ASTM number printed on the pipe. If you can’t identify it, call 888-251-3934 before ordering fittings.
Same “1 inch” name, nearly a 1/4" difference in actual size — the printed ASTM number matters more than the label.
Which Fittings Do You Need?
We sell and recommend Philmac Compression Fittings (IPS-OD) — sized to fit over the outside of your pipe, the standard for ranch water lines — for use with HDPE SDR 11 IPS-OD pipe. Tool-free, no insert stiffeners required, using a compression nut and grab ring for a secure, leak-free seal.
Note: Philmac IPS-OD compression fittings are optimized for SDR 11 pipe. For SDR 9, SDR 13.5, or SDR 17 pipe, please contact us to confirm fitting compatibility before ordering.
Pick your pipe size below to see prices and order the fittings most people need for it.
3/4" — most common lateral size
| Fitting | Use | Price |
|---|---|---|
| Coupling | Join two pipe runs | $13.79 |
| Male Adapter | Pipe to threaded valve/pump | $9.70 |
| Female Adapter | Threaded fitting to pipe | $17.48 |
| Standard Tee | Branch the mainline | $28.09 |
| End Cap | Terminate a line | $12.83 |
1" — most common mainline size
| Fitting | Use | Price |
|---|---|---|
| Coupling | Join two pipe runs | $20.15 |
| Male Adapter | Pipe to threaded valve/pump | $12.54 |
| Female Adapter | Threaded fitting to pipe | $17.76 |
| Standard Tee | Branch the mainline | $28.54 |
| End Cap | Terminate a line | $16.35 |
1-1/4", 1-1/2", and 2" — larger mainlines
| Fitting | 1-1/4" | 1-1/2" | 2" |
|---|---|---|---|
| Coupling | $33.09 | $40.81 | $51.48 |
| Male Adapter | $19.87 | $23.67 | $29.57 |
| Female Adapter | $26.28 | $31.38 | $44.22 |
| Standard Tee | $49.78 | $63.57 | $86.16 |
| End Cap | $24.23 | $33.77 | $41.21 |
► Other fittings — elbows, ball valves, repairs, and more
| Fitting | Project Use |
|---|---|
| Repair Coupling (No Stop) | In-line repairs on existing pipe runs without cutting out a section |
| Reducing Coupling | Stepping down pipe size from mainline to lateral or distribution lines |
| Standard Elbow | 90° direction changes around terrain, buildings, or obstacles |
| Female Elbow | 90° direction change with female thread outlet for connecting valves or risers |
| Female Tee | Branching off mainline with a female thread outlet for valves, hydrants, or meters |
| Reducing Standard Tee | Tapping a smaller lateral line off the mainline without reducing main flow |
| Shut Off Ball Valve Tee Handle | Isolation and shutoff points along mainline or at zone entries |
| Joint Kit | Replacement seals and grip ring for restoring a worn or leaking Philmac connection |
| PVC Grip Ring | Replacement grip ring for securing pipe in compression fitting body — despite the name, it’s not for PVC pipe |
See the full Philmac Compression Fittings collection for sizes and current prices. Stepping down pipe size? See Reducing Couplings. Need a shutoff point? See Ball Valves.
What Does SDR Mean, and Which One Do I Need?
SDR (Standard Dimension Ratio) tells you how thick the pipe wall is relative to its size — and that thickness is what determines how much pressure it can handle. Lower number, thicker wall, higher pressure rating.
| SDR Rating | Wall Thickness | Pressure Rating (@ 73°F) | Best For |
|---|---|---|---|
| SDR 9 | Heaviest | ~250 PSI | High-pressure mainlines, deep burial, pump-fed systems |
| SDR 11 | Heavy | 200 PSI | Standard agricultural mainlines and laterals — most common |
| SDR 13.5 | Medium | ~160 PSI | Lower-pressure distribution lines, gravity-fed systems |
| SDR 17 | Light | ~125 PSI | Low-pressure applications, large-diameter mains — not yet available, contact us |
SDR 11 is what we stock and sell — the standard choice for most ranch and farm water systems.
Pipe Specs, Size by Size
SDR 11 — 200 PSI (Most Common for Agricultural Use)
| Size | OD | Wall Thickness | ID | Pressure Rating |
|---|---|---|---|---|
| 3/4" | 1.050" | 0.095" | 0.860" | 200 PSI @ 73°F |
| 1" | 1.315" | 0.120" | 1.075" | 200 PSI @ 73°F |
| 1-1/4" | 1.660" | 0.151" | 1.358" | 200 PSI @ 73°F |
| 1-1/2" | 1.900" | 0.173" | 1.554" | 200 PSI @ 73°F |
| 2" | 2.375" | 0.216" | 1.943" | 200 PSI @ 73°F |
| 3" | 3.500" | 0.318" | 2.864" | 200 PSI @ 73°F |
| 4" | 4.500" | 0.409" | 3.682" | 200 PSI @ 73°F |
► Other SDR ratings — reference only, not currently purchasable
| SDR | Size | OD | Wall Thickness | ID | Pressure Rating |
|---|---|---|---|---|---|
| SDR 9 | 1" | 1.315" | 0.146" | 1.023" | ~250 PSI @ 73°F |
| SDR 9 | 1-1/4" | 1.660" | 0.184" | 1.292" | ~250 PSI @ 73°F |
| SDR 9 | 1-1/2" | 1.900" | 0.211" | 1.478" | ~250 PSI @ 73°F |
| SDR 9 | 2" | 2.375" | 0.264" | 1.847" | ~250 PSI @ 73°F |
| SDR 13.5 | 1" | 1.315" | 0.097" | 1.121" | ~160 PSI @ 73°F |
| SDR 17 | 2" | 2.375" | 0.140" | 2.095" | ~125 PSI @ 73°F |
SDR 9 and SDR 13.5 are not currently active in our catalog, and SDR 17 is not yet published.
How Big Is 1-Inch Pipe, Actually?
The spec tables above give exact numbers, but numbers alone don’t always tell you what something looks like. Here’s roughly what each size feels like next to something familiar.
Drawn to scale relative to each other, not to true size on your screen — screens vary too much in pixel density for any webpage to promise that. The dashed inner ring on each pipe marks roughly where the ID (inside diameter, where water actually flows) sits for SDR 11.
| Nominal Size | OD | Roughly the Size Of… |
|---|---|---|
| 3/4" | 1.050" | A US quarter, just a bit bigger |
| 1" | 1.315" | A D battery |
| 1-1/4" | 1.660" | A golf ball |
| 1-1/2" | 1.900" | A tennis ball |
| 2" | 2.375" | A hockey puck, laid flat |
| 3" | 3.500" | A soup can |
| 4" | 4.500" | A standard soda can |
What Size Pipe Do I Actually Need?
Now that you know your SDR, here’s the other half of the equation — matching pipe size to how much water you’re actually moving.
| Pipe Size | Typical GPM Range | Best Application |
|---|---|---|
| 3/4" | 3–9 GPM | Single trough, tank, or waterer supply line |
| 1" | 5–15 GPM | Small pasture lateral lines, 1–2 water points |
| 1-1/4" | 8–24 GPM | Multi-trough lateral distribution, small sub-mains |
| 1-1/2" | 10–30 GPM | High-demand laterals, sub-mains feeding multiple zones |
| 2" | 15–45 GPM | Main distribution lines, pump-fed mainlines |
| 3" | 35–100 GPM | High-volume mains, feedlot distribution, large operations |
| 4" | 60–175 GPM | Primary mains for large ranches, rural water systems |
Long runs, elevation changes, and multiple simultaneous water points can require a larger pipe than flow rate alone suggests. If those apply to your system, call us before ordering.
Questions We Hear a Lot
Tap any question to expand the answer.
Can I use Philmac IPS-OD fittings with SDR 9 or SDR 17 pipe?
Our Philmac IPS-OD fittings are built and tested for SDR 11 pipe specifically. They may work fine on SDR 9, 13.5, or 17, but we can’t guarantee a proper seal without confirming your exact pipe first — give us a call before ordering fittings for anything other than SDR 11.
Is this pipe safe for drinking water?
Yes — our HDPE pipe meets NSF-61 standards for potable water contact and is safe for drinking water, livestock watering, and food-grade agricultural applications.
What’s the difference between coil and reel format?
Coils (500–2,000 ft) are easier to handle manually and work well for smaller projects. Reels (2,500–10,000+ ft) are designed for machine-assisted burial and are ideal for large-scale contractor projects covering hundreds of acres.
| Format | Length Range | 1" Starting Price | 2" Starting Price | Best For |
|---|---|---|---|---|
| Coil | 500–2,000 ft | $438.90 (500 ft) | $1,039.50 (500 ft) | Smaller runs, manual handling, no special equipment needed |
| Reel | 2,500–10,000+ ft | $3,685.00 (4,000 ft) | $5,254.70 (2,500 ft) | Long continuous runs, fewer joints, machine-assisted burial |
Prices shown are current starting points for common sizes — see the full HDPE Water Pipe collection for all lengths and sizes in stock.
How many couplings, tees, and adapters do I need for a typical run?
A basic mainline run (well to trough, no branches) usually needs one Male Adapter at the well/pump end, a Coupling every time you join two pipe lengths, and a Female Adapter or End Cap at the trough end. Add a Tee for every branch off the mainline.
Why are some fittings showing out of stock?
Fitting demand can outpace restocking on popular sizes. Check the product page for current availability — if something’s backordered, contact us for the fastest way to get it.
Do you sell SDR 9 or SDR 13.5 pipe?
SDR 11 is our standard, actively stocked pipe. SDR 9 and SDR 13.5 are not currently active in our catalog — contact us if your project specifically requires one of these.
Do I need insert stiffeners with Philmac compression fittings?
No — Philmac IPS-OD compression fittings do not require insert stiffeners when used with SDR 11 HDPE pipe. The compression nut and grab ring provide a secure connection without additional support.
How deep should I bury HDPE pipe?
Minimum burial depth is typically 18–24" in most agricultural applications. In areas subject to freezing, bury below the local frost line — typically 36–48" in northern climates. Check local codes for your area.
Can HDPE pipe handle freezing temperatures?
HDPE is freeze-resistant — it expands slightly under freeze pressure rather than cracking like PVC or metal pipe. However, water inside the pipe can still freeze and block flow if it isn’t buried below frost depth.
What’s the pressure rating of SDR 11 vs. SDR 9?
SDR 11 (what we stock) is rated 200 PSI. SDR 9, if you ever need it, is rated approximately 250 PSI — a heavier wall for higher-pressure or pump-fed applications.
Can I connect different pipe sizes together?
Yes — use a Reducing Coupling to step down from a larger mainline to a smaller lateral, or a Reducing Tee to branch a smaller line off a larger main without reducing mainline flow.
Do I need a Joint Kit for every fitting?
A Joint Kit (replacement seals and grip ring) restores a fitting that’s lost its seal or grip — it’s not something you need on hand for every fitting up front, just for servicing one that starts to leak.
How do I connect pipe to a threaded valve or trough?
Use a Male Adapter when connecting to a female-threaded fitting (valve, pump, trough inlet), or a Female Adapter when connecting to a male-threaded fitting.
What does HDPE stand for?
HDPE stands for High-Density Polyethylene — a thermoplastic polymer used in agricultural water systems for buried mainlines and laterals. Flexible, freeze-resistant, corrosion-proof, and rated for 50+ years of service life underground.
How long does HDPE pipe last?
HDPE pipe is rated for 50+ years of service life when properly installed and buried. Unlike PVC or metal pipe, HDPE doesn’t corrode, scale, or become brittle with age underground.
Where Does Each Fitting Actually Go?
The tables above tell you what each fitting does — here’s what that looks like laid out in a real system, well to mainline to laterals to trough.
Simplified layout — not to scale. Every fitting above links back to the fitting tables for the right size and price.
Go Deeper
This guide covers what to buy and how to size it. If you want the full technical standards, real ranch installs, or help paying for the project, these connect straight through:
Specs & standards
- HDPE Pipe Technical Reference— ASTM/AWWA/NSF standards, joining methods, trenching and hydrostatic testing in full depth
- HDPE Pipe vs. PVC Pipe: Which Is Better for Livestock Watering Systems?
- Using HDPE Water Pipe in Ranching Systems— real-world ranch installs
- HDPE Water Pipe Installation Guide For Rotational Grazing
Fittings & valves
Planning your system
Paying for it
- EQIP & Cost-Share Funding Guide— buried water lines qualify for USDA cost-share (NRCS practices 516 & 614)
Shop
- HDPE Water Pipe
- Philmac Compression Fittings
- Water Systems— the full livestock watering lineup: pipe, fittings, valves, troughs, and tanks
Build Your Water System
You’ve got the specs. Now get the pipe and fittings to match — right the first time.