Tesco Steel & Engineering manufactures puddle flanges (water-stop / wall-seal flanges) — flanges welded onto a pipe where it passes through a concrete wall, floor, or structure and then cast into the concrete. The embedded flange creates a water-tight barrier (water stop) that blocks water seeping along the pipe–concrete interface, and anchors the pipe in the wall. Made to ASME, ANSI, MSS SP, and DIN standards in A105, SS 304/316/321, Duplex, Monel, Inconel, and Hastelloy. Standard or custom dimensions. ISO 9001:2015 certified. Made in India.
Puddle Flange (Water-Stop Flange)
Puddle flanges seal pipe penetrations through water-retaining concrete. Tesco Steel & Engineering manufactures them to ASME/ANSI/MSS SP/DIN or to drawing in the full material range — similar in concept to embedded anchor flanges; see also our special products and flange dimensions charts.
| Type | Construction | Use |
|---|---|---|
| Single-Plate Puddle Flange | One radial plate/collar welded to the pipe | Standard water-stop for most wall & floor penetrations |
| Double-Plate Puddle Flange | Two plates spaced along the pipe | Higher water-head / critical water-retaining structures |
| Puddle Flange with Water-Bar | Plate with a serrated/grooved edge or water-bar | Enhanced seal on demanding penetrations |
| Puddle Flanges are available in the following specifications: | |
|---|---|
| Size | 1/2"NB to 56"NB |
| Class | 150#, 300#, 3000#, 6000#, 9000# |
| Sch (Schedule) | XS, XXS, STD & Schedule 20, 40, 80, 160 |
| Pressure Ratings | PN 1 - PN 400 |
| Stainless Steel Puddle Flanges | ASTM A 182 F - 304 / 304H / 304L / 316 / 316H / 316L / 316Ti, 309, 310, 317L, 321, 347, 904L |
| Duplex Steel Puddle Flanges | ASTM A 182 - F 51, F 53, F 55 |
| Alloy Steel Puddle Flanges | ASTM A 182 - F5, F9, F11, F21, F22 & F91 |
| Carbon Steel Puddle Flanges | ASTM A 105 |
| Low Temp. Carbon Steel Puddle Flanges (LTCS Puddle Flanges Flanges) | A 350 LF2 |
| Copper Nickel (Cu-Ni) Puddle Flanges | C70600, 90/10, C71500, 70/30, C71640 |
| Nickel Puddle Flanges | UNS N02200, UNS N02201 |
| Monel Puddle Flanges | UNS N04400, UNS N05500, Alloy 20 |
| Inconel Puddle Flanges | UNS N06600, UNS N06601, UNS N06625, UNS N08800, UNS N08810, UNS N08825 |
| Hastelloy Puddle Flanges | UNS N10276, UNS N06022, UNS N10665, UNS N06455 |
| Titanium Puddle Flanges | Gr. 1, Gr. 2, Gr. 3, DTH 3.7035, DTH 3.7055 |
| Other Services | Hot Dip Galvanized (GI) Puddle Flanges Sand Blasting on Puddle Flanges Shot Peening on Puddle Flanges Epoxy Coating on Puddle Flanges FBE Coating on Puddle Flanges |
The embedded plate blocks seepage along the pipe–concrete interface, keeping tanks, basements, and structures water-tight.
Provides a water stop and anchors the pipe in the wall, resisting movement at the penetration.
Single-plate for standard penetrations and double-plate for higher water heads and critical structures.
A105, LTCS, SS 304/316/321, Duplex, Monel, Inconel, and Hastelloy — corrosion-resistant grades for water/wastewater & marine.
Made to ASME/ANSI/MSS SP/DIN or fully to the project drawing — plate diameter, thickness, and position to suit the wall.
Manufactured with full traceability and EN 10204 3.1 material test certificates on request.
| Material | Properties | Typical Use |
|---|---|---|
| A105 Carbon Steel / A350 LF2 (LTCS) | Strong, economical (often coated) | General concrete penetrations |
| SS 304 / 316 / 316L | Corrosion resistant | Water & wastewater tanks, treatment plants |
| SS 321 | Stabilised for high temperature | Hot-line penetrations |
| Duplex 2205 / Super Duplex 2507 | High strength & chloride resistance | Seawater, marine & desalination structures |
| Monel / Inconel / Hastelloy | Excellent corrosion resistance | Aggressive / chemical-service penetrations |
| Application | Use | Why Puddle Flange |
|---|---|---|
| Water & Wastewater | Tank & treatment-plant pipe penetrations | Water-tight seal; SS corrosion resistance |
| Pump Houses & Sumps | Wall & floor penetrations | Stops seepage; anchors pipe |
| Basements & Foundations | Below-ground pipe entries | Blocks groundwater ingress |
| Dams & Reservoirs | Water-retaining structures | Double-plate for high head |
| Marine & Ports | Seawater structures | Duplex / Copper-Nickel resistance |
| Power & Process Plants | Service-line penetrations | Standard & custom plate sizes |
| Tunnels & Civil Works | Pipe crossings through concrete | Sealed, anchored penetrations |
| Desalination | Seawater intake/outfall structures | Super-duplex chloride resistance |
Q1. What is a puddle flange?
A puddle flange is a flange (plate or collar) welded around a pipe where it passes through a concrete wall, floor, or tank and then cast into the concrete. It acts as a water stop — projecting into the concrete to block water seeping along the pipe–concrete interface — and anchors the pipe in the structure, keeping the penetration water-tight.
Q2. What is a puddle flange used for?
To seal pipe penetrations through water-retaining or below-ground concrete — water and wastewater tanks, treatment plants, pump houses, basements, dams, and marine structures — preventing water from tracking along the pipe through the wall, and anchoring the pipe.
Q3. How does a puddle flange stop water?
By projecting radially into the concrete, it greatly lengthens the path water would have to travel to get along the pipe–concrete interface. Cast solidly into compacted concrete with a continuous weld to the pipe, it forms a barrier (water stop) that blocks seepage through the wall.
Q4. What is the difference between a single-plate and double-plate puddle flange?
A single-plate puddle flange has one radial plate and suits most wall and floor penetrations. A double-plate puddle flange has two plates spaced along the pipe, giving two water-stop barriers for higher water heads and critical water-retaining structures. A water-bar edge can further enhance the seal.
Q5. What materials are puddle flanges made from?
Carbon steel (A105, usually coated) and LTCS for general work, and SS 304/316/321, Duplex, Monel, Inconel, or Hastelloy where corrosion resistance is needed — common for water, wastewater, seawater, and chemical-service penetrations. The grade is chosen for the fluid and environment.
Q6. How is a puddle flange installed?
It is continuously welded around the pipe, positioned centrally in the wall/floor thickness in the formwork with adequate concrete cover, and then cast into the concrete, which is compacted to leave no voids against the plate. The concrete is cured before water pressure or pipe loads are applied.
Q7. How is a puddle flange different from an anchor flange?
Both are embedded in concrete, but their primary jobs differ. A puddle flange is mainly a water stop — it seals the pipe penetration against water seepage. An anchor flange is mainly structural — it resists axial pipe loads (thrust, expansion). A puddle flange also helps anchor the pipe, and the two concepts overlap in below-ground work.
Q8. Can puddle flanges be supplied to our drawing and certified?
Yes. We manufacture puddle flanges to ASME/ANSI/MSS SP/DIN or to your drawing — pipe size, plate diameter, thickness, single/double plate, and material — with EN 10204 3.1 material test certificates on request. Send your wall and pipe details for a recommendation and quote.