Demco Series NE-C Lug Butterfly Valve

The Demco Series NE-C Butterfly Valve is widely recognized as one of the most durable resilient-seated butterfly valves in the industry, specifically designed for dependable, long-term performance across a broad spectrum of general and heavy-duty applications. The lug style body allows the valve to be installed as an end-of-line service valve (at a reduced pressure rating) or between flanges.

Sizes 2 to 12 in [50 to 300 mm] are available in both wafer and lug styles. This series is a general-purpose valve with a neck length designed to provide full clearance for the valve top over 2 in of insulation on ASME Class 150 pipe flanges.

Key Features

Durable Resilient Seat: The valve utilizes a hard-backed cartridge seat that is field-replaceable without specialized tools.² This design ensures ease of installation and reliable, bubble-tight shut-off.
Dry Stem Journal: The unique stem-hole design in the disc creates a dry stem journal, which minimizes the potential for leakage to the atmosphere and protects the stem assembly from the process media.
One-Piece Body: Features a robust, one-piece body casting (available in both wafer and tapped-lug patterns) for reduced weight and increased structural strength.
Bi-Directional Sealing: Provides reliable sealing with flow in either direction.
Positive Stem Retention: Includes a blowout-proof stem design for enhanced safety.
High Flow Disc: Designed for minimal resistance and high flow capacity.

General Specifications

Parameter	Detail
Series	NE-C
Body Style	Lug (also available in Wafer)
Sizes	2 to 12 in [50 to 300 mm]
Body Material	Ductile Iron (Standard), Carbon Steel, Stainless Steel, Bronze
Disc Material	Nickel-Plated Ductile Iron (Standard), Bronze, Stainless Steel, Aluminum Bronze
Stem Material	$416$ Stainless Steel (Standard), $316$ Stainless Steel (Optional)
Actuation	Lever Handle (Ten-Position Locking), Gear Operator (Handwheel), Bare Stem
Neck Length	Long Neck (Designed to clear $2''$ of pipe insulation on ASME Class 150 flanges)

Pressure Ratings

The Demco NE-C offers multiple drop-tight shut-off pressure ratings depending on size and application:

Size Range (Metric/Imperial)	Standard Shut-off Rating	High-Pressure Rating	End-of-Line Rating (Lug Only)
$2''$ to $12''$ ( $50$ to $300\,\text{mm}$ )	$200\,\text{psi}$	$285\,\text{psi}$	$200\,\text{psi}$ (with downstream piping removed)
$14''$ to $36''$ ( $350$ to $900\,\text{mm}$ )	$150\,\text{psi}$	N/A	$150\,\text{psi}$ (with downstream piping removed)