Dwyer DS-300 User Manual

Series DS-300 Flow Sensors

Installation and Operating Instructions Flow Calculations

1-15/16 (49.21)

1-5/8 (41.27) TYP

Bulletin F-50

Series DS-300 Flow Sensors are averaging pitot tubes

that provide accurate, convenient flow rate sensing. When purchased with a Dwyer Capsuhelic®for liquid flow or Magnehelic®for air flow, differential pressure gage of appropriate range, the result is a flow-indicating system delivered off the shelf at an economical price. Series DS-300 Flow Sensors are designed to be inserted in the pipeline through a compression fitting and are furnished with instrument shut-off valves on both pressure connections. Valves are fitted with 1/8˝ female NPT connections. Accessories include adapters with 1/4˝ SAE 45° flared ends compatible with hoses supplied with the Model A-471 Portable Capsuhelic®kit. Standard valves are rated at 200°F (93.3°C). Where valves are not required, they can be omitted at reduced cost. Series DS-300 Flow Sensors are available for pipe sizes from 1˝ to 10˝.

1/4 MALE NPT

1-3/4 (44.45)

1-11/16 (42.86)

5/16 (7.94)

Location - The sensor should be installed in the flowing line with as much straight run of pipe upstream as possible. A rule of thumb is to allow 10 - 15 pipe diameters upstream and 5 downstream. The table below lists recommended up and down piping.

PRESSURE AND TEMPERATURE

Maximum: 200 psig (13.78 bar) at 200°F (93.3°C).

Upstream and Downstream Dimensions in

Downstream

Upstream Condition

One Elbow or Tee

Terms of Internal Diameter of Pipe

Minimum Diameter of Straight Pipe

Upstream

In-Plane Out of Plane

INSPECTION

Inspect sensor upon receipt of shipment to be certain it is as ordered and not damaged. If damaged, contact carrier.

Two 90° Bends in

Same Plane

Two 90° Bends in

Different Plane

INSTALLATION General - The sensing ports of the flow sensor must be

Reducers or Expanders

correctly positioned for measurement accuracy. The instrument connections on the sensor indicate correct

All Valves**

positioning. The side connection is for total or high pressure and should be pointed upstream. The top connection is for static or low pressure.

DWYER INSTRUMENTS, INC.

* Values shown are recommended spacing, in terms of internal diameter for normal industrial

metering requirements. For laboratory or high accuracy work, add 25% to values.

** Includes gate, globe, plug and other throttling valves that are only partially opened. If valve is to

be fully open, use values for pipe size change. CONTROL VALVES SHOULD BE LOCATED

AFTER THE FLOW SENSOR.

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

P.O. BOX 373 • MICHIGAN CITY, INDIANA 46361, U.S.A. Fax: 219/872-9057 e-mail: info@dwyer-inst.com

POSITION

Be certain there is sufficient clearance between the mounting position and other pipes, walls, structures, etc, so that the sensor can be inserted through the mounting unit once the mounting unit has been installed onto the pipe.

Flow sensors should be positioned to keep air out of the instrument connecting lines on liquid flows and condensate out of the lines on gas flows. The easiest way to assure this is to install the sensor into the pipe so that air will bleed into, or condensate will drain back to, the pipe.

For Air or Gas Flow

UPPER PIPE

Install in upper quadrant of pipe

QUADRANT

Condensate drains

back to pipe

For Liquid or Steam Flow

Install in lower quadrant of pipe

Air bleeds

back to pipe

INSTALLATION

1. When using an A-160 thred-o-let, weld it to the pipe wall. If replacing a DS-200 unit, an A-161 bushing (1/4˝ x 3/8˝) will be needed.

2. Drill through center of the thred-o-let into the pipe with a drill that is slightly larger than the flow sensor diameter.

3. Install the packing gland using proper pipe sealant. If the packing gland is disassembled, note that the tapered end of the ferrule goes into the fitting body.

4. Insert sensor until it bottoms against opposite wall of the pipe, then withdraw 1/16˝ to allow for thermal expansion.

5. Tighten packing gland nut finger tight. Then tighten nut with a wrench an additional 1-1/4 turns. Be sure to hold the sensor body with a second wrench to prevent the sensor from turning.

INSTRUMENT CONNECTION

Connect the slide pressure tap to the high pressure port of the Magnehelic®(air only) or Capsuhelic®gage or transmitting instrument and the top connection to the low pressure port.

See the connection schematics below.

Bleed air from instrument piping on liquid flows. Drain any condensate from the instrument piping on air and gas flows.

Water Flow

LP BLEED

INCHES OF WATER

.40

.20

CAPSUHELIC®

MAX. OPERATING PRESS. 500 PSIG

DWYER INSTRUMENTS, INC MICHIGAN CITY, INDIANA 46360 U.S.A.

ZERO SET

LOWER PIPE

QUADRANT

1/16 (1.59)

CLEARANCE

HP BLEED

.60

.80

1.0

PIPE

FLOW

SENSOR

1-7/16 (36.53)

Open valves to instrument to place flow meter into service. For permanent installations, a 3-valve manifold is recommended to allow the gage to be zero checked without interrupting the flow. The Dwyer A-471 Portable Te st Kit includes such a device.

Air or Gas Flow