The vapor seal fittings
have always
needed.
YODI™ is the industry's first pre-cut, pre-sized intermediate vapor barrier for pipe fitting insulation. Zero permeability. Installed in minutes — not hours.
0.00
Perms Vapor Transmission
3-Ply
Composite Membrane
-100°F to +300°F
Rated
Pre-Cut
Installation Ready
The Problem
Field mastic, tacks, and PVC tape leave vapor pathways at every fitting.
The NIA calls pipe fittings "the highest risk of vapor infiltration" in any below-ambient system. Field-applied mastics are subject to installer variability, curing conditions, and seam failures. PVC tape over a fitting cover is not a vapor barrier — it is a vapor pathway waiting to happen.
The YODI™ Solution
Factory-sealed. Pre-cut. Zero permeability — before the PVC cover goes on.
YODI™ installs over the fitting insulation and under the PVC or metal protective cover — creating a continuous, third-party tested, zero-permeability membrane at every fitting. No mastic. No field guesswork. No vapor infiltration.
How It Works
Three simple steps. Zero vapor infiltration.
01
Place the insulation insert
Wrap the supplied pre-cut fiberglass insert — or existing rigid cellular glass, Polyiso, or molded fiberglass fittings — around the bare pipe fitting.
02
Apply the YODI™ cover
Slide the pre-sized YODI™ membrane over the insulated fitting. The flexible 3-ply composite conforms perfectly to elbows, tees, valves, flanges, and reducers.
03
Install the PVC or metal cover
Finish with your standard JM Zeston or Proto PVC fitting cover. YODI™ is the complete vapor barrier underneath — fully sealed before any protective cover is applied.
Where YODI™ Works
Built for demanding applications
Chilled Water Systems
Below-ambient piping where continuous vapor barrier integrity is code-required at all fittings.
Dual-Temp Systems
Systems cycling between heating and cooling modes demand reliable vapor control at every fitting transition.
Commercial HVAC
Large-scale mechanical rooms, hospitals, data centers, and process facilities where callbacks are not an option.
Why YODI™
Engineered for zero failure
True zero permeability
ASTM E96 Method A tested at 0.00 perms. Not "vapor resistant" — vapor proof. ASTM C1136-12 Type IX certified.
Dramatically faster installation
Pre-sized and pre-cut for every fitting type. No measuring, no trimming, no mastic cure time. Many times faster than traditional methods.
Resilient 3-ply membrane
130 PSI burst strength. 30 lb/in. tensile. Flexible construction conforms to complex geometry without cracking. Rated −100°F to +300°F.
Manufacturer-approved
Fully compliant with JM Zeston PVC and Proto PVC manufacturer requirements. ASTM E84 · 25/50 flame/smoke rated.
Technical Specifications
Tested. Certified. Proven.
Third-party tested to the most rigorous industry standards.
| Property | Test Method | Result |
|---|---|---|
| Water vapor transmission | ASTM E96 Method A | 0.00 perms ★ |
| Flame / smoke rating | ASTM E84 | 25/50 ✓ |
| Burst strength | ASTM D774 | 130 PSI |
| Tensile strength | ASTM D828 | 30 lb/in. |
| Mold & mildew resistance | ASTM C1338 | No growth |
| Humidity resistance | ASTM C1258 | Pass |
| Dimensional stability @ 150°F | ASTM D1204 | <0.25% change |
| Operating temp — membrane | — | -100°F to +300°F |
| Operating temp — insert | — | -20°F to +1,000°F |
| Vapor retarder classification | ASTM C1136-12 | Type IX |
| Total product thickness | Micrometer | 2.4 Mils |
| Weight per area | Scale/Balance | 23 lbs/1,000 sq.ft. |
★ Zero permeability is the defining feature of the YODI™ system.
At fittings, elbows, tees, and other irregular surfaces, the vapor retarder must be maintained with the same rigor as on straight pipe runs. These locations represent the highest risk of vapor infiltration due to the difficulty of achieving continuous membrane coverage with field-fabricated jacketing.
NIA Mechanical Insulation Design Guide · Published in cooperation with ASHRAE / NIBS
Certifications & Patents
Tested, patented, and approved
U.S. Patent 11,378,221
ASTM C1136-12 Type IX
ASTM E84 · 25/50
JM Zeston PVC Approved
Proto PVC Approved
ASHRAE 90.1
ASTM C1338 — No growth
ASTM C795 — Stainless steel safe