Dwyer Insite™ IS/PX/TX Series In-Line Flowmeter
Specifications, Installation, and Operating Instructions
Product Overview
The Dwyer Instruments Series IS/PX/TX Insite™ Air/Liquid In-Line Flowmeter is designed for accurate flow measurement in a variety of applications. Available in multiple materials including PVC, aluminum, brass, and 316 stainless steel, these flowmeters offer versatility. An optional field-adjustable reed switch is available for high and low alarm indication.
The flowmeter operates by using a piston, guided by a spring, which moves against the fluid flow. The position of the piston's knife edge, visible through the transparent housing, aligns with a printed scale to indicate the flow rate.
Key Features:
- Available in PVC, aluminum, brass, or 316 stainless steel wetted materials.
- Optional reed switch for alarms.
- Mountable in any orientation.
- O-ring sealed straight threads for leak-free connections.
- Teflon® tape recommended for NPT pipe threads.
Specifications
| Service | Compatible gases or liquids |
| Wetted Materials | Flowtube: PVC or Polysulfone; Fittings: Aluminum, brass, 316 SS, PVC, or PVDF; Seal: Viton® or Kalrez® |
| Temperature Limits | See model chart |
| Pressure Limits | See model chart |
| Switch Type | Optional 3-wire reed switch |
| Electrical Rating | 0.3 A @ 120 VAC/100 VDC |
| Accuracy | ±5% FS; 3 GPM: ±7% FS |
| Process Connections | 1/2", 3/4", 1", or 1-1/2" selectable |
| Weight | 0.8 to 2.6 lb (0.36 to 1.09 kg) |
| Compliance | CSA (switch only) |
Temperature and Pressure Limits
PVC Flowtube
| Fluid Temperature | Max. Pressure | ||||
|---|---|---|---|---|---|
| °F | °C | psig | bar | psig | bar |
| 70 | 21 | 200 | 13.79 | 60 | 4.1 |
| 100 | 38 | 100 | 6.90 | 50 | 3.41 |
| 125 | 52 | 75 | 5.17 | 35 | 2.41 |
Polysulfone with 316 SS Fittings
| Fluid Temperature | Max. Pressure | ||||
|---|---|---|---|---|---|
| °F | °C | psig | bar | psig | bar |
| 210 | 99 | 200 | 13.8 | 60 | 4.1 |
Polysulfone with PVDF Fittings
| Fluid Temperature | Max. Pressure | ||||
|---|---|---|---|---|---|
| °F | °C | psig | bar | psig | bar |
| 120 | 49 | 150 | 10.35 | - | - |
Model Chart
The following chart details various model configurations based on series, range, process connection, material, and options. Specific ranges are listed below.
| Example Model Format | Series | Range Examples (Low - High) | Process Connection | Connection Material | Seal Material | Options | Description |
|---|---|---|---|---|---|---|---|
| PX-30GPM-8-F-F | PX | 3 GPM water (3 GPM*) - - 5 GPM water - - 10 GPM water - - 15 GPM water - - 20 GPM water - 20 GPM 30 GPM water - 30 GPM 40 GPM water - 40 GPM 50 GPM water - 50 GPM 20 LPM water - - 38 LPM water - - 55 LPM water - - 75 LPM water - 75 LPM 110 LPM water - 110 LPM 150 LPM water - 150 LPM 200 LPM water - 200 LPM 50 SCFM air - 50 SCFM 100 SCFM air - 100 SCFM 135 SCFM air - 135 SCFM 200 SCFM air - 200 SCFM 300 SCFM air - 300 SCFM 400 SCFM air - 400 SCFM 500 SCFM air - 500 SCFM 1400 SLPM air - 1400 SLPM 2500 SLPM air - 2500 SLPM 3600 SLPM air - 3600 SLPM 5500 SLPM air - 5500 SLPM 8000 SLPM air - 8000 SLPM 11000 SLPM air - 11000 SLPM 14000 SLPM air - 14000 SLPM | 4 (1/2") 6 (3/4") 8 (1") 12 (1-1/2") | D (Aluminum) F (Brass) I (316 SS) M4 (PVDF - IS only) V (PVC - PX and TX only) | F (Viton®) | EP (SS shaft/spring - IS only) IS1 (1 switch kit) IS2 (2 switch kits) IS1T (1 switch kit - IS/TX) IS2T (2 switch kits - IS/TX) ST (SS identification tag) | PVC tube flowmeter Polysulfone tube flowmeter |
*Only available with PX series.
Installation
The flowmeter body is marked with "IN" and "OUT" ends, and an arrow on the scale indicates flow direction. Mounting can be in any orientation without affecting performance.
- Connect end fittings to the plastic body using O-ring sealed straight threads. Do not overtighten, use sealant, plumbing tape, or pipe dope.
- For NPT pipe threads, use Teflon® tape and standard torques for leak-free connections.
- When piping the meter inline, use a wrench only on the end fittings, not on the plastic body.
- Consider installing a disconnect fitting upstream for easier removal and control valves downstream.
Diagram: Flowmeter Operation
Fluid enters the "IN" port, forcing the piston to move against spring pressure. The piston's knife edge, visible through the transparent housing, aligns with the printed scale to indicate the flow rate.
Diagram: Dimensional Drawings
- Overall length: 7 inches [177.80 mm]
- Body width: 2 inches [50.80 mm]
- Connection width: 3 inches [76.20 mm]
Operating Instructions
Fluid enters the "IN" port, pushing the piston against spring pressure. The piston's movement is restricted by the flow rate. The knife edge of the piston, visible through the transparent housing, aligns with the printed scale to display the flow rate.
Air Flowmeter Calibration and Correction Factors
Air flowmeters are calibrated at 90 psi pressure and 70°F temperature, reading in SCFM/SLPM. For accurate readings at different pressures or temperatures, apply correction factors from the tables below.
To obtain corrected SCFM readings when operating at pressures other than 90 psig or temperatures other than 70°F, multiply the SCFM reading on the tube by the applicable factor.
NOTICE: Refer to the pressure and temperature chart to determine appropriate operating limits.
Table 1: Pressure Correction Factors
| psig | Factor |
|---|---|
| 10 | .49 |
| 20 | .58 |
| 30 | .65 |
| 40 | .72 |
| 50 | .79 |
| 60 | .84 |
| 70 | .90 |
| 80 | .95 |
| 90 | 1.00 |
| 100 | 1.05 |
| 110 | 1.09 |
| 120 | 1.13 |
| 125 | 1.16 |
Table 2: Temperature Correction Factors
| Temperature °F | Factor |
|---|---|
| 30 | 1.04 |
| 50 | 1.02 |
| 70 | 1.00 |
| 90 | 0.98 |
| 100 | 0.97 |
| 120 | 0.96 |
| 125 | 0.95 |
Recommended Filtration
A system filtration of at least a 74-micron filter or a 200-mesh screen is recommended. Inadequate filtration can lead to meter failure, often in the open position. Proper filtration ensures meter components function correctly and prevents premature wear.
Replacement Parts
The following table lists replacement part numbers for various models.
| Flow Rates and Connection Sizes | PX-3, 5, 10, and 15 | PX-20, 30, 40, and 50 | IS-5, 10, and 15 | IS-20, 30, 40, and 50 | Description | |
|---|---|---|---|---|---|---|
| Flow tube assembly | 1161-AS | - | 1119-AS | - | Flow tube assembly with max. flow reading | |
| 1158-AS | - | 1116-AS | - | |||
| 1159-AS | - | 1117-AS | - | |||
| 1160-AS | - | 1147-AS | 1173-AS | |||
| - | 1148-AS | - | 1174-AS | |||
| - | 1149-AS | - | 1175-AS | |||
| - | 1150-AS | - | 1176-AS | |||
| End fittings for NPT line sizes and materials | 1/2 | 1194-4 | - | 1194-4 | - | Aluminum |
| 3/4 | 1194-6 | 1196-6 | 1194-6 | 1196-6 | ||
| 1 | 1194-8 | 1196-6 | 1194-8 | 1196-6 | ||
| 1-1/2 | - | 1196-12 | - | 1196-12 | ||
| 1/2 | 1193-4 | - | 1193-4 | - | Brass | |
| 3/4 | 1193-6 | 1195-6 | 1193-6 | 1195-6 | ||
| 1 | 1193-8 | 1195-8 | 1193-8 | 1195-8 | ||
| 1-1/2 | - | 1195-12 | - | - | ||
| 1/2 | 1188-4 | - | 1188-4 | - | 316 SS | |
| 3/4 | 1188-6 | 476-6 | 1188-6 | 476-6 | ||
| 1 | 1188-8 | 476-8 | 1188-8 | 476-8 | ||
| 1-1/2 | - | 476-12 | - | 476-12 | ||
| 1/2 | 1191-4 | - | - | - | PVC* | |
| 3/4 | 1191-6 | 477-6 | - | - | ||
| 1 | 1191-8 | 477-8 | - | - | ||
| 1-1/2 | - | 477-12 | - | - | ||
| Seal | 2 (required) | 1112 | 396 | 1112 | 396 | Viton® seal |
*Not available on IS units.
Switch Kits
Flowmeters can be equipped with one or two electric switches to trigger signals at specific flow rates. These switches are supplied as field-installable kits.
Each kit includes a ring-shaped ceramic magnet that fits around the flowmeter piston and a proximity switch in a housing that clamps to the body. As the piston moves, the magnet's field trips the switch. An adjustment screw allows for precise setting of the actuation point.
Switch Specifications:
- Max. rating: 8 watts @ 120 VAC/100 VDC.
- Wires: Black (normally open), Blue (normally closed), White (common).
- Contact ratings: 12 VDC @ 0.66 A, 28 VDC @ 0.285 A, 120 VAC @ 0.066 A (at 77°F).
Switch Kit Order Numbers:
- For 3 to 15 GPM: Order No. ISS-15-B
- For 20 to 50 GPM: Order No. ISS-50-B
Note: A single switch has a 25% of full-scale operating band, allowing it to function as a deviation alarm.
Switch Installation
Follow these steps for installing switch kits:
- Install the magnet: Disassemble the flowmeter. Place the magnet between the piston and spring. Ensure the piston is correctly oriented and the spring is seated. Reassemble the flowmeter.
- Install the foam gasket: Peel off the protective paper and press the gasket firmly onto the switch housing.
- Install the switch housing(s):
- Single switch: Push capscrews through housing tabs and thread into half-collars. Use washers; nuts may be discarded.
- Dual switches: Align tabs on both housings, push capscrews through collar tabs. Secure with nuts and washers. Half-collars and extra magnets may be discarded.
Note: Switch housing orientation is flexible. Install to suit wiring and adjustment needs.
Diagram: Insite Switch Parts Description
- 1. Housing
- 2. Gasket
- 3. Magnet
- 4. Half-Collars (2)
- 5. Capscrews (4)
- 6. Capscrew Nuts (2)
- 7. Switch
- 8. Switch Carrier
- 9. Adjustment Screw
- 10. O-Ring (2)
- 11. Retainer Clip
- 12. Lockwashers (4)
- 13. 1/2" NPTF Conduit Connection
Setting the Switch Points
Flowmeter Installed: Adjust flow to position the piston at the desired indicator level. Turn the adjustment screw clockwise until the switch actuates. Use an ohmmeter to confirm actuation. Repeat for a second switch if applicable.
Flowmeter Not Installed: Simulate flow by pushing a tool (e.g., pencil eraser) through the inlet end to move the piston against spring pressure. Position the knife edge at the desired reading. Turn the adjustment screw clockwise until the switch actuates. Use an ohmmeter to confirm. Repeat for a second switch if applicable.
Note: Ensure sufficient lead length for switch wires to allow full travel.
Maintenance and Repair
Periodic cleaning of the tube and internal parts is the primary maintenance. Use wrenches only on end fittings when removing the flowmeter from the line. Avoid applying wrenches to the plastic body.
To clean, remove the outlet end fitting and then the shaft, piston, and spring assembly. Inspect parts for damage. Clean the tube interior and parts with a soft dry cloth. If necessary, use water and mild non-abrasive soap. DO NOT USE SOLVENT OF ANY KIND.
Replace any worn or damaged parts. When reassembling, ensure the piston is correctly oriented. Inspect O-rings for damage and replace if necessary. Wet O-rings with water before assembly to improve sealing.
Warranty and Return
Refer to Dwyer Instruments' "Terms and Conditions of Sale" for warranty information. Contact customer service for a Return Materials Authorization (RMA) number before returning any product for repair. Include a brief description of the problem and any relevant application notes.
