Butterfly Valves:

Butterfly ValvesButterfly Valves

One of the most durable of all resilient-seated butterfly valves in the industry, this valve excels in a wide variety of applications. Cast in both wafer and tapped-lug patterns in a wide variety of material choices, DEMCO butterfly valves feature a one-piece body for minimum weight and maximum strength. The unique stem hole design in the disc ensures a dry stem journal and the hard-backed seat allows ease of installation, reliable operation, and is field-replaceable without special tools. DEMCO butterfly valves are available in sizes 2 in. through 36 in. (50 mm through 900 mm).

Engineered for long-term, maintenance-free performance, DEMCO butterfly valves are commonly selected for a variety of applications spanning a wide range of industries:

  • Chemical and Petrochemical
  • Agriculture
  • Oil and gas drilling production
  • Food and beverage
  • Water and waste water
  • Cooling towers (HVAC)
  • Power
  • Mining and materials
  • Dry bulk handling
  • Marine and Government


Bi-directional sealing
This valve provides bi-directional sealing at full rated pressure with identical flow from either direction.

Integral flange seal
Molded into the edge of the seat is an integral flange seal which accommodates ASEM weld neck, slip-on, threaded and socket flanges as well as “stub end” type C flanges.

ASME Class 150 rating
Body rating is ASME Class 150 (285 psi non-shock). Wafer body diameters are designed to self-center in ASME Class 150 flange patterns.

Butterfly Valves Styles:

Series NE-C
Sizes 2 in. through 12 in. (50 mm through 300 mm), this series is a general purpose valve with neck length designed to provide full clearance of the valve top over two inches of insulation on ASEM Class 150 pipe flanges; available both wafer and lug styles.

Series NE-I
Sizes 2 in. through 12 in. (50 mm through 300 mm), it is suited for a wide range of applications in many industries, including food and beverage utilities and process flow lines. This short neck design is offered in a wide variety of body materials. The valves are designed for installation between ASME Class 125/150 flanges.

Series NE-D Valve
Sizes 2 in. through 12 in. (50 mm through 300 mm), it is a short neck valve with body notches to fit popular lightweight flange patterns, making it ideal for bulk material handling and the transportation industry. Valves will also center in ASME Class 125/150 flanges.

Series NF-C
Sizes 14 in. through 36 in. (350 mm through 900 mm) are available in both wafer and lug styles. The wafer body has two drilled locator lugs at top and bottom for ASME Class 150 flanges. Bronze bearings are installed on both stems for minimum operating torque.


Gate Valves:

DEMCO® Series DM Gate ValvesDEMCO® Series DM Gate Valves

DEMCO® Series DM Gate Valves, the premier designed Gate Valve in the oil and gas drilling market, specifically engineered for the rigorous requirements of oilfield applications.

Designed for dependable, heavy duty performance in abrasive service conditions, DEMCO DM gate valves are commonly selected for a number of oilfield applications, including:

  • Drilling standpipe manifold
  • Pump manifold block valves
  • High pressure mud mixing lines
  • High pressure drilling system block valves
  • Wellheads
  • Well treating and frac service
  • Production manifolds
  • Production gathering systems
  • Production flow lines

The DEMCO Series DM Gate Valves are available in ASME Classes 400, 600, 900 and 1500.
Features and Benefits

  • In line field reparability, the bonnet easily removed for internal parts inspection and/or replacement
  • Flexible trim offerings, make easier to trim valves for a wide range of service conditions
  • Double acting thread design for fast operation
  • Exclusive seat design for drop tight sealing, provide a drop-tight shut-off in abrasive and erosive service

Download DEMCO Gate Valves Catalog for more details and specifications


Features and Benefits

  • In-line field reparability, the bonnet easily removed for internal parts inspection and/or replacement
  • Heavy duty roller bearings, heavy duty stem roller bearings reduce torque on 4 inch (100mm) and larger valves.
  • Floating slab gate design, providing a tighter pressure responsive seal
  • Unique, abrasion resistant, one-piece seat design
  • Locking seat alignment, the seat assembly is engineered with a metal “lock shell” that aligns the seat in the bottom of the valve.
  • Body wear rings-absorbing erosive wear that can damage the body around the seat bore area.
  • Rising stem design-indicates gate position.
  • Replaceable stem packing-without removing the bonnet from the valve.
  • Flow cleansed design, prevents the valve from “sanding up”.

Download DEMCO Gate Valves Catalog for more details and specifications.


DEMCO Series DT/DB Gate Valves are recognized for their quality design, rugged dependability and corrosion resistance, particularly for use in waterflood and CO2 applications.

DEMCO Aluminum Bronze and Stainless Steel Valves and Accessories are designed especially for the demanding requirements of corrosive CO2 injection and waterflood applications in the enhanced oil recovery market.

Features and Benefits:


  • In-line field reparability-bonnet easily removed for inspection/replacement
  • Corrosion resistant materials are standard, body and bonnet materials as well as all internal wetted parts comply with NACE RP-0475
  • Rising stem design, the handle moves up and down on the bonnet providing visible aid to determine whether the valve is open or closed.
  • Superior abrasion resistance, Buna-N elastomer encapsulated seats also provide an excellent deterrent to abrasion.
  • Four ring stem packing set, preventing leakage into the stem journal and outside the valve
  • Non wetted stem thread design, preventing stem seizure and assuring long trouble free valve performance.
  • Accessories, Ball check valves, flow tees and strainers are available to complete requirements for an entire injection assembly.


Download DEMCO Gate Valves Catalog for more details and specifications.

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Naing Win
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+65 6505-9200

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