Tesco Steel & Engineering manufactures drip rings — open-bore flange spacer rings with a tapped drain hole fitted between two flanges to drain (drip off) condensate or liquid that collects in a line. The drain tapping at the bottom of the ring connects to the pipe bore, so liquid can be bled off through a small valve or plug without breaking the joint. A drip ring is the drain-duty form of a bleed ring (test ring). Made to the matching ASME B16.5 flange in A105, SS 304/316/321, Duplex, Monel, Inconel, and Hastelloy. Class 150 to 2500, PN1 to PN400. ISO 9001:2015 certified. Made in India.
Drip Ring (Flange Drain Ring)
Drip rings give a simple, permanent drain point at a flange — useful on steam, gas, and process lines where liquid pools. Tesco Steel & Engineering manufactures drip rings, bleed rings, ring spacers, and paddle spacers to the matching flange standard — dimensioned per the table below; see the flange dimensions charts.
| Item | Tapping | Primary Function |
|---|---|---|
| Drip Ring | Tapped hole at the bottom | Drain (drip off) condensate / liquid by gravity |
| Bleed / Test Ring | Tapped hole (top or as needed) | Vent, drain, pressure-test, inject or sample |
| Ring Spacer | No tapping | Fills the flange gap; keeps the line open |
A drip ring is a bleed ring set up for draining (bottom tapping); a plain ring spacer has no tapping. They share the same open-bore spacer body.
| Drip Rings 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 Drip Rings | ASTM A 182 F - 304 / 304H / 304L / 316 / 316H / 316L / 316Ti, 309, 310, 317L, 321, 347, 904L |
| Duplex Steel Drip Rings | ASTM A 182 - F 51, F 53, F 55 |
| Alloy Steel Drip Rings | ASTM A 182 - F5, F9, F11, F21, F22 & F91 |
| Carbon Steel Drip Rings | ASTM A 105 |
| Low Temp. Carbon Steel Drip Rings (LTCS Drip Rings Flanges) | A 350 LF2 |
| Copper Nickel (Cu-Ni) Drip Rings | C70600, 90/10, C71500, 70/30, C71640 |
| Nickel Drip Rings | UNS N02200, UNS N02201 |
| Monel Drip Rings | UNS N04400, UNS N05500, Alloy 20 |
| Inconel Drip Rings | UNS N06600, UNS N06601, UNS N06625, UNS N08800, UNS N08810, UNS N08825 |
| Hastelloy Drip Rings | UNS N10276, UNS N06022, UNS N10665, UNS N06455 |
| Titanium Drip Rings | Gr. 1, Gr. 2, Gr. 3, DTH 3.7035, DTH 3.7055 |
Drip Ring Dimension Diagram
| NPS | ID | OD by Pressure Class | ||||
| 150 | 300 | 600 | 900 | 1500 | ||
| 1 | 28.6 | 63.5 | 69.9 | 69.9 | 76.2 | 76.2 |
| 1.1/2 | 41.3 | 82.6 | 92.1 | 92.1 | 95.3 | 95.3 |
| 2 | 54 | 101.6 | 108 | 108 | 139.7 | 139.7 |
| 2.1/2 | 63.5 | 120.7 | 127 | 127 | 161.9 | 161.9 |
| 3 | 79.4 | 133.4 | 146.1 | 146.1 | 165.1 | 171.5 |
| 4 | 104.8 | 171.5 | 177.8 | 190.5 | 203.2 | 206.4 |
| 6 | 155.6 | 219.1 | 247.7 | 263.5 | 285.8 | 279.4 |
| 8 | 203.2 | 276.2 | 304.8 | 317.5 | 355.6 | 349.3 |
| 10 | 257.2 | 336.6 | 358.8 | 396.9 | 431.8 | 431.8 |
| 12 | 304.8 | 406.4 | 419.1 | 450.9 | 492.1 | 514.4 |
Bottom tapping drains condensate or liquid from the line by gravity, preventing pooling and corrosion at low points.
The bore matches the pipe ID, so the ring stays permanently in the line with no flow restriction.
Sized to the matching ASME B16.5 flange and facing, with the drain tapping size and position to suit the duty.
A105, SS 304/316/321, Duplex, Monel, Inconel, and Hastelloy for corrosive and high-temperature service.
Tapped to take a drain valve or plug so liquid can be bled off without breaking the flanged joint.
Manufactured to the matching flange standard or your drawing, certified with EN 10204 3.1 MTC.
| Material | Properties | Typical Use |
|---|---|---|
| A105 Carbon Steel / A350 LF2 (LTCS) | Strong, economical; LF2 for low temp | Non-corrosive & low-temperature lines |
| SS 304 / 316 / 321 | Good corrosion resistance; 321 high-temp | Process, chemical & high-temperature lines |
| Duplex 2205 / Super Duplex 2507 | High strength & chloride resistance | Seawater & offshore service |
| Monel 400 / Inconel | Excellent in HF, marine & high-temp | HF, seawater & high-temperature lines |
| Hastelloy | Superior acid resistance | Aggressive chemical service |
| Industry | Typical Use | Why Drip Ring |
|---|---|---|
| Power Generation | Steam-line & condensate drains | Drains condensate; SS 321 high-temp |
| Oil & Gas | Liquid drain at flanged joints | Gravity drain without breaking the joint |
| Refinery & Petrochemical | Low-point drains on process lines | Permanent drain; full material range |
| Gas Distribution | Condensate knock-out drains | Removes liquid from gas lines |
| Chemical Plants | Drain & purge points | Monel / Inconel / Hastelloy |
| Compressed Air | Moisture/condensate drains | Drains water from air lines |
| Offshore & Marine | Low-point liquid drains | Duplex / alloy corrosion resistance |
| Water & Utilities | Drain points at flanges | Economical open-bore drain |
Q1. What is a drip ring?
A drip ring is an open-bore spacer ring fitted between two pipe flanges with a tapped drain hole at the bottom. It lets condensate or liquid collecting in the line be drained (dripped) off through a small valve or plug at the flanged joint without dismantling it. The open bore keeps flow unrestricted.
Q2. What is the difference between a drip ring and a bleed ring?
They share the same open-bore tapped-spacer design. A drip ring is set up specifically for draining — the tapping is at the bottom so liquid drains by gravity. A bleed ring (test ring) is the more general version whose tapping is used to vent, drain, pressure-test, inject, or sample. A drip ring is essentially a bleed ring dedicated to the drain duty.
Q3. Where is the tapping located on a drip ring?
At the bottom (lowest point) of the ring, so condensate or liquid settling in the line drains out by gravity through the tapping. The ring is oriented during installation so the drain hole is at the low point.
Q4. Does a drip ring restrict flow?
No. Its bore matches the pipe inside diameter, so the process flows through unrestricted while the ring stays permanently in the line. Only the small drain tapping connects to the bore.
Q5. What sizes, classes, and materials are available?
Drip rings are made to match ASME B16.5 flanges in Class 150 to 2500 (PN1 to PN400), sized 1/2" to 56", in A105/LTCS, SS 304/316/321, Duplex, Monel, Inconel, and Hastelloy — with the drain tapping size to suit the duty.
Q6. What is a drip ring used for?
Draining condensate from steam and gas lines, removing liquid that pools at low points, knocking out moisture from compressed-air and gas lines, and providing a permanent drain point at a flange. A drain valve or plug fitted to the tapping controls the drainage.
Q7. How is a drip ring different from a ring spacer?
Both are open-bore spacers fitted between flanges. A ring spacer simply fills the flange gap with no connection; a drip ring has a tapped drain hole into the bore so it also provides a gravity drain point. Choose a drip ring when you need to drain liquid at the flange.
Q8. Can drip rings be supplied to our drawing and certified?
Yes. We supply drip rings, bleed rings, and ring spacers to the matching flange standard or your drawing — size, class, facing, material, and drain tapping detail — with EN 10204 3.1 material test certificates on request. Send your line details and the drain required for a quote.