Dwyer MMA-31-LV Mini-Master Flowmeter
The Dwyer MMA-31-LV is a Mini-Master® Series MMA variable area flowmeter that reads 1 to 16 GPH water directly on a 2 in. (51 mm) scale with ±4% FS accuracy. It is the Series MMA flowmeter without configurable valve, with a transparent Nylon 12 body rated to 100 psi with a compression fitting and 130°F.
Specifications verified October 14, 2026 against the Dwyer Series MM catalog (pp. 250-251) and Bulletin F-49 Rev. 9 (9/19).
Best For
- Direct reading of 1 to 16 GPH water on a 2 in. scale
- Chemical injectors
- Medical equipment
- Panel or surface mounted installations with minimal space
Warranty
Dwyer warrants this product for one year from delivery to the buyer under its standard warranty, unless a product-specific warranty supplied with the product states another period. Damage due to contact with incompatible gases or liquids is not covered by warranty, so confirm compatibility before placing the meter in service.
Key Features
Direct-Reading 2 in. Scale
Reads 1 to 16 GPH water directly with ±4% FS accuracy. Side printed scale graduations give an instant reading, and a white back on the flow tube makes the float easier to see.
No Configurable Valve
Supplied without the configurable valve. On vacuum service, install any flow control valve on the discharge side of the flowmeter.
Transparent Nylon 12 Body
Precision-molded transparent nylon offers high chemical resistance and high repeatability, and disassembles with the provided key for cleaning.
Up to 100 psi with Compression Union
Rated 100 psi (6.9 bar) with a 5/16 in. compression union and 50 psi (3.4 bar) with the spring tubing clamp. Temperature limit is 130°F (54°C).
Panel or Surface Mounting
Panel mount through two 11/32 in. holes on 3 in. centers with spring retainer clips, or snap the meter into a plastic mounting clip on a horizontal surface. Install the meter vertically.
Compact, Low Installation Cost
The compact body needs minimal panel space and mounts easily, keeping installation costs low.
ZOT Supply is an authorized distributor of Dwyer products.
Technical Specifications
| Specification | MMA-31-LV |
|---|---|
| Model | MMA-31-LV |
| Series | Mini-Master® Series MMA |
| Flow Range | 1 to 16 GPH water |
| Range Number | 31 |
| Scale Length | 2 in. (51 mm) |
| Accuracy | ±4% FS |
| Service | Compatible gases and liquids |
| Temperature Limit | 130°F (54°C) |
| Pressure Limit | 100 psi (6.9 bar) with compression fitting; 50 psi (3.4 bar) with tubing clamp |
| Valve | Without configurable valve |
| Body Material | Nylon 12 (transparent) |
| O-Rings | Buna-N (optional materials available) |
| Float | Black glass, K monel, stainless steel or tungsten carbide |
| Process Connection | 5/16 in. OD for push-on rubber or plastic tubing with provided spring tubing clamp; connect to rigid tubing with a double compression fitting |
| Mounting | Vertical installation required. Panel mount through two 11/32 in. holes on 3 in. centers with spring retainer clips, or surface mount with plastic mounting clip and #4 Phillips B-type self-tapping screws |
| Weight | 1 oz (28.35 g) |
| Accessory | A-327 5/16 in. union |
| Compliance | Meets the technical requirements of EU Directive 2011/65/EU (RoHS II) |
Documentation
Frequently Asked Questions
What flow range does the Dwyer MMA-31-LV measure?
The MMA-31-LV reads 1 to 16 GPH water directly on a 2 in. (51 mm) scale with ±4% FS accuracy.
What pressure and temperature is the Dwyer MMA-31-LV rated for?
The pressure limit depends on the connection: 25 psi max with 1/4 in. ID x 3/8 in. OD plastic tubing slipped at least 3/8 in. onto the connections; 50 psi max with the same tubing and spring type tubing clamps installed on both connections; 100 psi (6.9 bar) max with a suitable 5/16 in. compression union and metal or semi-rigid plastic tubing. The temperature limit is 130°F (54°C).
Does the Dwyer MMA-31-LV include a valve?
No. The MMA-31-LV is supplied without the configurable valve. The Dwyer MMA-31 is the same range with the field configurable valve.
Where does the flow control valve go on vacuum service?
On vacuum service, install any flow control valve on the discharge side of the MMA-31-LV and keep the inlet piping short and open so the meter operates at or near atmospheric pressure.
How is the Dwyer MMA-31-LV mounted?
Install it vertically. For panel mounting, drill two 11/32 in. holes on 3 in. centers on a vertical line, insert the meter from the front and push on the spring retainer clips from the rear. For surface mounting, attach the plastic mounting clip to a horizontal surface with #4 Phillips B-type self-tapping screws and snap the meter into the clip.
How do I clean the Dwyer MMA-31-LV?
Wash the body and parts in a mild soap and water solution; a cotton swab or soft bristle brush helps clean the flow tube. Avoid solvents and liquid soaps and avoid prolonged immersion. Coat O-rings with silicone stop cock grease or petroleum jelly when reassembling.
What is the Dwyer MMA-31-LV made of?
The body is transparent Nylon 12, O-rings are Buna-N, and the float is black glass, K monel, stainless steel or tungsten carbide.
- Series:
- MM
- Product Type:
- Variable Area Flowmeter
- Media:
- Water
- Flow Range:
- 1-16 GPH
- Connection Type:
- Push-On Tubing
- Connection Size:
- 5/16 in. OD
- Body Material:
- Nylon 12
- Max Pressure:
- 100 psi
- Max Temperature:
- 130°F
- Accuracy:
- ±4% FS
- Valve:
- None
- Mounting:
- Vertical
- NIST Calibration:
- Available
