Concentric Disc Rubber Lined Butterfly Valve Lug Type | Resilient Seated | CI DI | EPDM NBR | Supplier India

Description

Concentric Disc Rubber Lined Butterfly Valve — Lug Type | Resilient Seated | CI / DI Body | EPDM / NBR | IS 13095 / EN 593 / API 609 | KELOR

Supplier: Krishna Industries (KELOR) – Ahmedabad, Gujarat, India
Established: 2017 | GSTIN: 24AKLPP6499B1ZT | IEC: AKLPP6499B
MOQ: 10 Nos | Body: CI / DI | Disc Design: Concentric (Resilient Seated)
Standard: IS 13095 / EN 593 / API 609 Category A | Sizes: DN40–DN600

Concentric Disc Rubber Lined Butterfly Valve — Lug Type Supplier in India

Krishna Industries (KELOR), based in Ahmedabad, Gujarat, is a B2B supplier of Concentric Disc Rubber Lined Butterfly Valves in Lug Type body — Cast Iron (CI) and Ductile Iron (DI) body — concentric disc (resilient seated) — EPDM, NBR, Natural Rubber, and Neoprene seat lining — SS304, SS316, and DI disc — lug body — PN10 / PN16 — DN40 to DN600 — lever, gear, pneumatic, and electric actuated — IS 13095 / EN 593 / API 609 Category A — ISO 5211 mounting pad — GST invoice — MOQ 10 Nos — Pan India dispatch from Ahmedabad.

The concentric disc butterfly valve — also called resilient seated butterfly valve, rubber lined butterfly valve, or zero-offset butterfly valve — is the standard industrial butterfly valve for water supply, HVAC, ETP/STP, irrigation, cooling water, and general chemical utility service at PN10 and PN16. The disc shaft runs through the centre of the disc and the valve bore — the disc is concentric to the rubber seat liner — on closing, the disc presses uniformly against the rubber seat across its full circumference, producing a bubble-tight seal. This page covers the lug body configuration specifically — see related products below for wafer body variants.

Concentric vs Double Offset vs Triple Offset — Butterfly Valve Disc Design Guide

For 90% of Indian industrial utility applications at PN10/PN16 — water supply, HVAC, ETP, irrigation, cooling water, fire fighting — the concentric disc rubber lined butterfly valve is the correct and most economical specification. Double offset and triple offset are only justified when the application exceeds the pressure or temperature limits of rubber, or when cycle life is a critical concern.

Rubber Lining / Seat Material Guide

Technical Specifications

Lug Type — Dead-End and End-of-Line Service Explained

The primary reason to specify lug type over wafer type in a concentric disc butterfly valve is dead-end / end-of-line service capability. In a wafer type butterfly valve, the body is held in compression between two pipe flanges by through-bolts — if the downstream pipe flange is removed, the valve body is no longer supported and the upstream pressure will push the wafer body out of position. The valve cannot hold pressure with one side open.

In a lug type butterfly valve, bolts from the upstream pipe flange thread into the valve body lugs on the upstream side independently, and bolts from the downstream pipe flange thread into the lugs on the downstream side independently. The upstream side can hold pressure with the downstream flange completely removed — the valve is rated for dead-end service. This makes lug type the correct specification for:

• Valves at the end of a pipeline — tank inlet, vessel connection, equipment nozzle
• Maintenance points where one side of piping must be regularly removed without depressurising the upstream system
• Fire pump discharge headers — upstream pressure must be maintained while downstream sprinkler branches are serviced
• Any installation where single-side pipe removal is part of the operational or maintenance procedure

For standard in-line service where both pipe sides remain in place — wafer type is the correct and more economical specification. Specify lug type only when dead-end or end-of-line capability is a genuine operational requirement.

Applications in Indian Industries

• Municipal water supply distribution — DI EPDM PN16 — zone isolation valves, pumping station branch headers, overhead tank inlets — IS 13095 compliance — lug type for end-of-line tank inlet connections
• HVAC chilled water and condenser water — CI EPDM PN16 — AHU branch isolation, chiller plant headers — lug type for equipment connections where AHU or chiller must be isolated and removed independently
• Fire fighting systems — CI or DI EPDM PN16 — fire pump discharge headers, wet riser branch isolation — lug type for end-of-line fire hydrant and hose reel connections
• ETP and STP — CI EPDM PN10/PN16 — raw sewage inlet distribution, treated effluent outlet, sludge recirculation — lug type for pump connections requiring isolation without draining system
• Irrigation pump stations — CI or DI EPDM PN10 — pump discharge header branch isolation — lug type allows individual pump removal without shutting down other pumps
• Cooling tower pump headers — CI EPDM PN16 — individual pump isolation on multi-pump cooling water headers — lug type for pump maintenance access
• Industrial utility — oil and fuel service — CI NBR PN16 — fuel distribution headers, diesel day tank isolation — NBR lining for oil and fuel compatibility
• Mining and mineral slurry — DI Natural Rubber PN10 — raw water and slurry distribution headers — natural rubber lining absorbs abrasive particle impact better than EPDM

Related Products — Krishna Industries (KELOR)

• Lug Type Butterfly Valve — detailed installation guide, lug body specifications, end-of-line service requirements, bolt length guide
• PN16 Butterfly Valve — Wafer Type — wafer body concentric disc EPDM — more economical for standard in-line service where lug type not required
• Gear Operated Butterfly Valve — for DN200 and above where lever handle torque is excessive
• Double Flanged Butterfly Valve — for buried pipeline, large bore DN200+, municipal infrastructure where neither wafer nor lug body is suitable
• Teflon Lined Butterfly Valve — PTFE seat for aggressive chemical service where rubber lining is attacked by media

Frequently Asked Questions

1. What does “concentric disc” mean in a butterfly valve?

Concentric disc means the disc shaft runs through the exact centre of the disc and the valve bore — the disc is concentric to (shares the same centre as) the seat. On closing, the disc contacts the rubber seat simultaneously across its entire circumference. This is the simplest butterfly valve design — also called resilient seated or zero-offset. IS 13095, EN 593, and API 609 Category A all describe this design as “resilient seated butterfly valve.” It is the standard for PN10/PN16 water, HVAC, and utility service.

2. What is the difference between concentric and double offset butterfly valve?

In a concentric disc valve, the shaft is centred — the disc rubs against the rubber seat through the full 90° rotation. This contact causes gradual seat wear over many cycles. In a double offset valve, the shaft is offset from both the disc centre and the pipe centreline — the disc lifts away from the seat almost immediately on opening, eliminating rubbing through most of the rotation. Double offset (high performance) is specified for higher pressure (PN25+), higher cycle frequency, metal seat, and temperature above rubber limits. For standard Indian utility applications at PN16 with moderate cycle frequency, concentric disc is the correct and more economical choice.

3. When should I specify lug type instead of wafer type?

Specify lug type when: (1) the valve is at the end of a pipeline and the downstream side must be removable — tank inlet, equipment nozzle, vessel connection; (2) individual pump isolation is required on a multi-pump header without removing downstream piping; (3) fire pump discharge where upstream pressure must be maintained during branch servicing. For standard in-line service with no end-of-line requirement, wafer type is more economical and the correct choice.

4. Is EPDM or NBR lining standard?

EPDM is standard supply — suitable for water, steam to 120°C, dilute chemical, ozone, and chlorinated water. NBR is specified when the media contains oil, diesel, fuel, or petroleum products — EPDM swells in oil contact and fails rapidly. If your application is water service, EPDM. If oil or fuel, NBR. Confirm media before ordering — specifying the wrong rubber lining is the most common butterfly valve selection error.

5. What is the ISO 5211 mounting pad?

ISO 5211 is the international standard for actuator mounting interfaces on valves. The mounting pad on the valve stem top matches standard dimensions so that a lever handle, gear operator, pneumatic actuator, or electric actuator can be fitted using the same mounting bolt pattern. This means a valve supplied with lever handle can be upgraded to gear or actuated operation later without removing the valve from the pipeline — just unbolt the lever and bolt on the new actuator. Confirm ISO 5211 compatibility when ordering if future actuation is planned.

6. What is the MOQ?

MOQ is 10 Nos. Project orders — 20 to 500+ Nos across sizes — with hydro test reports, IS 13095 compliance documentation, and GST invoice. WhatsApp body material, lining, size list, and quantity for project pricing within 2 hours.

Conclusion

The Concentric Disc Rubber Lined Butterfly Valve — Lug Type — supplied by Krishna Industries (KELOR) is the resilient seated butterfly valve for dead-end service, end-of-line installation, and pump header isolation in Indian water supply, HVAC, fire fighting, ETP, irrigation, and industrial utility applications — CI and DI body — EPDM, NBR, Natural Rubber, Neoprene lining — SS304 disc — lug body — PN10 / PN16 / Class 150 — DN40 to DN600 — IS 13095 / EN 593 / API 609 Category A — lever, gear, pneumatic, and electric actuated — ISO 5211 mounting pad. GST invoice, Pan India dispatch from Ahmedabad. WhatsApp body material, rubber lining, size, and quantity for bulk pricing within 2 hours.