Dwyer EFS2 User Manual

Page 3

Fitting installation.

EFS2 Series meters require special fittings

that ensure that the flow sensor is installed to the correct

depth. The fitting must be installed in the pipeline before the

meter can be installed. For best results, install with at least

ten diameters of straight pipe upstream of the meter and

five diameters downstream (or more under specific adverse

circumstances). See diagrams, on page 3.

If there is not enough straight run to smooth out the turbu-

lence caused by valves, fittings, and changes in direction,

some decrease in accuracy may result. This does not mean

that the flow meter’s reading is meaningless, however. In

some applications (control systems, valve operation, chemi-

cal addition), a repeatable reading may be more important

than a highly accurate one.

Although EFS2 Series PVC meter tees are supplied with some

straight pipe, additional straight pipe should be added to

meet straight pipe recommendations. It is not advisable to

connect a flow-disturbing device (e.g. valve or elbow) directly

to the end of these fittings.

A PVC fitting is usually installed by solvent welding. The stain-

less steel and brass meter fittings have female pipe threads,

requiring the appropriate male threaded fittings. Saddle or

weld fittings (3” and above) require a hole to be cut in the

pipe. Recommended hole size is 1-3/4”.

chemical injection or Fertigation.

When any magmeter, by

any manufacturer, is used in a chemical injection application

(including fertigation), the chemical injection point must be

placed downstream of the magmeter OR far enough upstream

for complete mixing to occur before the fluid reaches the

meter. When unmixed chemical or fertilizer alternates with

water passing through the meter, the rapid changes in con-

ductivity may cause sudden spikes and drops in the meter’s

reading, resulting in inaccurate measurement. The magmeter

will restabilize, however, with a steady flow of fluid of uniform

conductivity.

inStallation

caution:

Never remove the U-clip retainer

when the pipe is under pressure. Always

remove pressure from the pipe before you

attempt to remove the meter. Removal under

pressure may result in damage or serious injury.

inStallation

StraigHt PiPE rEcommEnDationS

(X = pipe diameter)

Page 2

DiStortED FloWS

Distorted

Flow Profile

Faster Flow
causes meter
to read High

10X

Page 3

10X

20X

30X

50X

reduced Pipe

two Elbows in Plane

two Elbows, out of Plane

Expanded Pipe

Swirling Flow

Propeller meter

Partially open

butterfly Valve

Spiral Flow

Okay position if there is no

air in the pipe

PoSitioning tHE mEtEr

bESt PoSitionS

caution:

These flow sensors are not recom-

mended for installation downstream of a

boiler feedwater pump where installation

fault may expose the flow sensor to boiler

pressure and temperature. Maximum recommended

temperature is 130°F (Plastic), 200°F (Metal).

meter installation.

After the meter fitting is installed in the

pipeline, the meter can be installed in the fitting. After noting

the direction of the flow arrow, press the meter into the fitting

as far as it will go. Retain the meter in place by inserting the

U-clip. The pin can be installed from either side. It may be

necessary to rotate the probe back and forth slightly to start

the pin into the slots on the probe. Slide the pin in as far as

it will go.

caution:

In chemical injection or fertiga-

tion applications, install chemical injection

point downstream of magmeter, or far

enough upstream to allow complete mix-

ing of fluids before the meter.

EFS2