Cresline HD160 (SIDR-9) Plastic Polyethylene Pipe

What it is and where it fits

I’ve used plenty of options for moving cold water underground—PEX, PVC, and different grades of polyethylene—and this Cresline HD160 pipe has become one of my go‑tos for long, direct-burial runs where flexibility and pressure rating matter. It’s a black polyethylene line made to an SIDR‑9 standard and rated for 160 psi, which puts it squarely in the sweet spot for well supply lines, yard hydrants, and irrigation mains that see real pressure but don’t need the rigidity of PVC.

If you’ve only ever worked with PEX, think of this as a different species altogether. It’s not PEX, and it doesn’t behave like it. This is ID-controlled SIDR pipe intended to be used with insert (barb) fittings and clamps, not PEX crimp/expansion fittings. That distinction shapes almost everything about how you install and maintain it.

Build, sizing, and what those letters mean

The “HD160” tag indicates a 160 psi pressure rating (at standard temperature), while “SIDR‑9” is the inside-dimension ratio standard that dictates the wall thickness for a given internal diameter. The upshot: the pipe’s sizing is tied to its internal dimension, which helps maintain predictable flow through long runs. The flip side is compatibility; because the outside diameter can vary from what you’re used to with PEX or IPS HDPE, you need the right insert fittings that are intended for SIDR pipe.

The black jacket has carbon-black content for UV resistance during handling, but like most polyethylene, it’s fundamentally a direct-burial product. Don’t plan on leaving long stretches exposed in full sun for years. For underground use, the finish and roundness on my coil were good—no flat spots or noticeable ovaling—which matters when you’re pushing on barbed fittings.

A note on listings you might see: ignore “box dimensions” on product pages; they don’t describe the actual pipe size. What matters are the nominal size and the SIDR rating. Verify both before you buy, and match fittings accordingly.

Installation experience

I used this pipe for a cold-water supply line between a well head and a small outbuilding, through clay and rocky soil. Here’s what stood out during install:

• Uncoiling and handling: Like most PE pipe, it has memory. The easiest method is to roll it straight down the trench and let it relax in the sun if possible. In colder weather it’s stiffer and wants to keep its coil; in warm weather it behaves nicely.

• Bending: It tolerates broad, sweeping curves. Avoid tight bends; if in doubt, dig your trench to accommodate a gentler radius or use elbows. Kinking can happen if you force a sharp turn, and a kink is a permanent weak spot.

• Cutting and prepping: A ratcheting PVC/PE cutter makes clean, square cuts. Deburr the inside edge; a quick chamfer helps fittings start easier.

• Fittings and clamps: Use insert (barb) fittings designed for SIDR poly. I push the pipe fully home onto the fitting and use two stainless clamps per joint, spaced slightly apart and positioned over the barbs. Warming the pipe ends with hot water or a heat gun (carefully) helps in cold weather.

• Trench and bedding: It handled rocky soil well, but I still backfilled with screened material for the first few inches around the pipe to keep sharp edges off the wall. That extra effort pays off.

• Pressure test: After backfilling to half depth, I pressurized and held for a couple hours. No creep, no drop, and the joints stayed dry.

Compared to PEX, the install pace was similar for straight runs and easier across distance because the coils come in long lengths and the material cost per foot is typically lower. Compared to PVC, there’s less cutting and gluing, fewer joints, and no cure time—big advantages when the trench is open.

Performance and durability

• Pressure and flow: The 160 psi rating is ample for well pumps and municipal tie-ins that stay under typical residential pressures. Flow is excellent through long runs, owing to the smooth bore and consistent ID. As with any thermoplastic, remember that pressure ratings drop at elevated water temperatures; I only use this for cold water.

• Buried in rocky soil: No signs of scuffing through install, and post-backfill the line has remained stable. Polyethylene’s ability to flex with minor ground movement is a real advantage over rigid PVC in freeze/thaw areas.

• Freeze considerations: I don’t count on any plastic pipe to survive a hard freeze if water is trapped, but this material is more forgiving than rigid pipe. Proper burial depth remains the first line of defense.

• Above grade: Short, sun-exposed sections during install were a non-issue, but I don’t leave this exposed long-term. If you need above-ground permanence, sleeve or shield it.

Compatibility and common pitfalls

This is where people get tripped up, so it’s worth being explicit:

• It is not PEX. Do not use PEX crimp, clamp, or expansion fittings on it. The wall thickness and OD are different, and you won’t get a reliable seal or mechanical hold.

• Use insert/barb fittings made for SIDR polyethylene. Match your nominal pipe size, and verify with the fitting manufacturer that it’s appropriate for SIDR-9 PE.

• Push-to-connect fittings: Some are rated for CTS/PEX OD, not SIDR PE. Don’t assume compatibility.

• Potable water: If you’re running drinking water, check that your specific coil is labeled for potable use (NSF/ANSI 61 or equivalent) and that local code accepts SIDR polyethylene for your application. The Cresline branding is established, but jobsite acceptance is ultimately about markings and code.

Who it’s for

• Rural wells and yard hydrants
• Long irrigation mains and branch lines
• Conduit for low-voltage wire runs (with pull string)
• Temporary bypass lines where quick deployment matters

If you’re after a rigid, straight-line installation with precise above-grade terminations, PVC might be better. If you need interior distribution with tight bends and fixtures, PEX wins. For long, underground, cold-water runs in rough terrain, this HD160 pipe hits a very practical balance.

What I liked

• Strong pressure rating for typical residential/agricultural use
• Flexible enough to navigate terrain without dozens of joints
• Straightforward install with readily available barb fittings
• Resilient in rocky backfill and tolerant of ground movement
• Cost-effective across long distances

What could be better

• Sparse product listings can cause sizing confusion; buyers need clear SIDR/nominal size info and potable certifications up front
• Coil memory in cold weather can slow installation
• Limited compatibility with popular push-to-connect and PEX systems means more planning at transitions

Tips to get the most out of it

• Lay the coil in the sun before install to relax memory
• Use two stainless clamps per barb, oriented 180 degrees apart
• Bed and initial backfill with sand or screened soil to protect the wall
• Pressure test before full backfill; fix weeps early
• Label and document any transition fittings for future maintenance

The bottom line

The Cresline HD160 pipe is a dependable, practical choice for buried, cold-water applications where you want flexibility, solid pressure capacity, and fewer joints. It’s not a drop-in PEX substitute and shouldn’t be treated as one; success depends on matching it with the right SIDR-compatible insert fittings and respecting its bend limits. Do that, and it performs exactly as you’d hope—especially in uneven, rocky ground where rigid pipe struggles.

Recommendation: I recommend this pipe for well lines, irrigation mains, and similar cold-water, direct-burial projects where long runs and ground movement are part of the equation. It installs cleanly, holds pressure, and stays out of trouble underground. Just be diligent on sizing and fittings, and verify potable ratings and local code if you’re using it for drinking water.