Name: DEMCO Series NE-D Lightweight-Flange Butterfly Valve, 2″–12″
Brand: DEMCO
SKU: IH-VAL-BFLY-NED
Availability: BackOrder

Question 1

Is the NE-D a wafer or lug butterfly valve?

Accepted Answer

Wafer only (with body notches for lightweight flange patterns). Wafer bodies install between two flanges using through-bolts and self-centre in ASME Class 150 flange patterns. Lug bodies have threaded bolt holes. Specify the body configuration explicitly on your RFQ.

Question 2

What sizes are available in the DEMCO NE-D?

Accepted Answer

2″ – 12″ (50 – 300 mm). Larger bores (14"–36" / 350–900 mm) are covered by the Series NF-C product line — please request the NF-C series instead if you need 14" or larger.

Question 3

Which shut-off pressure rating should I order?

Accepted Answer

200 psi (standard), 285 psi (high-pressure), 50 psi (low-torque), Throttling. The 200 psi rating is the standard general-service shut-off and covers the majority of applications. The 285 psi rating is for higher-pressure liquid service. The 50 psi rating is selected when the application allows reduced shut-off pressure in exchange for substantially smaller actuator sizing — common in automated systems where actuator cost dominates. Throttling-rated valves do not provide drop-tight closure but offer the lowest operating torque for control-valve service.

Question 4

How do I select the right seat elastomer?

Accepted Answer

Match the elastomer to your fluid and temperature: Buna-N is the general-purpose hydrocarbon and oil seat (0–180°F). EPDM is the recommended water-service elastomer (peroxide-cured, +20–275°F) and is also resistant to alkaline solutions. Viton is the premium chemical/high-temperature seat (+20–300°F). Hypalon is preferred in acid service. Refer to the DEMCO Material Selection Guide for chemical-specific compatibility — Indus Hydraulics will cross-check the elastomer against your service conditions during quote review.

Question 5

How do I select the right body and disc material?

Accepted Answer

Body material is driven by line-fluid corrosivity and pressure: ductile iron is the volume choice; bronze, stainless steel, aluminium and aluminium-bronze cover progressively more aggressive fluids; nickel-plated and PVF-coated ductile iron variants extend ductile iron's chemical service. Disc material should match the body material's corrosion class — DEMCO discs are available in 316 SS, Monel, aluminium, bronze, ductile iron (nickel-plated or PVF-coated), Alloy 20 and Hastelloy C. Indus Hydraulics will recommend a body/disc pairing on your RFQ once you confirm the line fluid and temperature.

Question 6

Can this valve be automated?

Accepted Answer

Yes. The DEMCO top-flange is dimensionally compatible with competitive butterfly valves, so any DEMCO 10-position locking handle, 2-position locking handle, memory-stop throttling handle, square-nut handle, weatherproof worm-gear operator, or Series DR double-acting / spring-return pneumatic actuator can be fitted in the field. With the optional "utility top" stem the valve also accepts third-party actuators without modification — useful when replacing a competitive valve in an existing automated installation.

Question 7

Is this valve fire-safe / NACE / API 607 rated?

Accepted Answer

No — the DEMCO NE/NF/NEI series is a resilient-seated process butterfly valve and does not carry API 607 fire-safe certification or NACE MR0175 certification. For fire-safe or sour-service applications, Indus Hydraulics carries triple-offset metal-seated butterfly valves under the Cameron oilfield valve product line — please request the oilfield butterfly valve series instead.

Question 8

Is end-of-line service supported?

Accepted Answer

End-of-line service is not supported on this body style. The NE-D is supplied wafer-only and requires both upstream and downstream flanges to constrain the valve in service. For end-of-line service requirements, specify the lug-body NE-C, NE-I or NF-C product line instead.

Position	Selection
Body Configuration	Wafer (1), Lug (5)
Body Material	Ductile Iron (1), Cast Iron wafer (2), Aluminium Bronze (3), Carbon Steel (4), Aluminium NE-I wafer only (5), ENC Coated DI (6), Stainless Steel (8)
Stem Material	416 SS (1), 316 SS (2), Monel (3)
Disc Material	316 SS (2), Monel (3), Aluminium (4), Ductile Iron (5), Vented (6), Solid SS (9), Alloy 20 (7), Hastelloy C (8)
Seat Elastomer	Buna-N (31), Black Neoprene (32), Hypalon (33), Viton (34), Peroxide-Cured EPDM (35), Natural Rubber (36), White Neoprene (37), ETM-30230 (01), Fluorosteam (02), Peroxide-Cured Buna-N (03)
Actuation	Bare Shaft (—), 10-Position Locking Handle (14), 2-Position Locking Handle (64), Throttling Memory-Stop Handle (24), Square Nut (5), Worm-Gear Operator, Series DR Pneumatic Actuator

Parameter	Value
ASME pressure class	ASME Class 150 (285 psi non-shock body rating)
Drop-tight shut-off ratings	200 psi (standard), 285 psi (high-pressure), 50 psi (low-torque), Throttling
Operating temperature range	−30°F to +300°F (−34°C to +149°C) — depends on selected elastomer
Vacuum rating	29.9 in Hg (sealed against 10 microns)
End-of-line service capable	no
Flow coefficient Cv (full open)	145 (2″) → 7,500 (12″)
Actuation options	Lever handles, worm-gear operators, Series DR pneumatic actuators

Parameter	Value
Body material options	Ductile iron, PVF-coated ductile iron, ENC nickel-coated ductile iron
Stem material options	416 stainless, 316 stainless, Monel
Disc material options	316 SS, Monel, aluminium, bronze, ductile iron, ENC nickel-plated ductile iron, vented, PVF-coated ductile iron
Seat elastomer options	Buna-N, Black Neoprene, Hypalon, Viton, EPDM (peroxide-cured), Natural Rubber, White Neoprene, ETM-30230, Fluorosteam

DEMCO Series NE-D Lightweight-Flange Butterfly Valve, 2″–12″

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Parameter	Value
Series	NE-D
Body configuration	Wafer only (with body notches for lightweight flange patterns)
Sanitary / FDA service	no