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Dwyer HF User Manual

Series hf in-line flow monitors, Dwyer instruments, inc

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Valve

Size

1/8 NPT

1/4 to 1/2 NPT

3/4 to 1 NPT

1-1/4 to 1-1/2 NPT

2 NPT

Series HF IN-LINE FLOW MONITORS

Specifications - Installation and Operating Instructions

BULLETIN F-55

Series HF Flow Monitors combine the
simplicity of a sharp edged orifice disk with a
variable area flow monitor to provide a low cost
way to measure flow at high pressures. These
monitors are tubular, with all internal wetted parts
sealed within the body casing. Running through
the body is a tapered shaft which is centered in
the bore by pilot disks at each end. Surrounding
the shaft are a sharp-edged floating orifice disk,
a transfer magnet and return spring. The disk
and transfer magnet are held in the “no flow”
position by a biased return spring. As flow moves
through the monitor, it creates a differential
pressure at the orifice disk forcing the disk and
transfer magnet against the return spring. As
flow increases, the differential pressure at the
disk increases, forcing the disk and transfer
magnet to move along the tapered center shaft.
As flow decreases, the biased return spring
forces the disk and transfer magnet down the
center shaft, returning to the “no flow” position.
In metal casing monitors, disk and magnet
movement are not visible so a magnet follower is
located outside the body casing, magnetically
coupled to the internal transfer magnet. As flow
increases, motion of the internal magnet moves
the magnet follower outside the body casing,
under the scale.

SPECIFICATIONS

Service: Compatible gases or liquids.
Wetted Materials: Body: Aluminum, brass or
304 SS; Seals: Buna-N or Fluoroelastomer;
Magnet: PTFE coated Alnico; Other internal parts:
304 SS.
Maximum Viscosity: 500 SSU.
Temperature Limits: HFA, HFL, HFB and HFS
Models: 240°F (116° C); HFH Models: 400°F
(204°C).
Pressure Limits: HFA Models: 600 psig (41 bar);
HFL, HFB and HFH Models: 3500 psig (240 bar);
HFS Models: 6000 psig (413 bar).
Accuracy: ±4% FS over entire range; ±2.5%
over center third of the measuring range.
Repeatability: ±1% of full scale.
Shipping Weight: 1/8 to 1/2˝ female NPT
Models; 2 lb (0.9 kg); 3/4 to 1˝ female NPT
Models: 3.5 lb (1.59 kg); 1-1/2˝ female NPT
Models: 11 lb (5 kg); 2˝ female NPT Models: 13.5
lb (6.12 kg).

("A")

("C")

("B")

“A”

Reference

1.25

1.875
2.375
3.500
3.500

“B”

Wrench Flats

0.875
1.250
1.750
2.250
2.250

“C”

Reference

4.813
6.562
7.125

10.125
12.625

DWYER INSTRUMENTS, INC.

Phone: 219/879-8000 www.dwyer-inst.com

P.O. BOX 373 • MICHIGAN CITY, IN 46361,U.S.A. Fax: 219/872-9057 e-mail: [email protected]

F-55:HF Bulletin 7/24/09 9:54 AM Page 1