RKA-1

Supported Applications

The Dwyer RKA series Regulator Kits are designed for use with Rate-Master® and Visi-Float® flowmeters to provide a regulated constant differential pressure between the flowmeter inlet and outlet. This function maintains nearly constant flow in systems experiencing fluctuating inlet or discharge pressures. The regulator is used in applications such as liquid level measurement and orifice purging.

Operating Conditions & Performance

The series maintains a constant pressure differential of approximately 3 PSIG, ±0.15 PSIG. To operate correctly, the inlet supply must provide at least 3 PSIG above the flowmeter discharge pressure. The standard regulator is compatible with any Dwyer flowmeter up to 200 SCFH.

Configuration Options

The RKA series includes specific kits tailored for different model configurations, each containing a complete set of components for assembly and installation. All variants feature a process connection of 1/4" NPT. Wetted materials across the series include Brass, Aluminum, and a Nylon reinforced Buna N diaphragm.

Kit contents vary by specific application:

• RKA (Rate-Master® A): Includes a Regulator assembly, 1/4" Tubing – Aluminum, 1/4" NPT X 1/8" SPT Reducing nipple, 1/8" NPT X 1/4" Tubing comp. Elbow-brass, 1/4" NPT X 1/4" tubing comp. connector-brass, and a 1/4" NPT Street Tee – Brass.
• RK-VFB (Visi-Float® B): Includes the same components as RKA: Regulator assembly, Aluminum tubing, reducing nipple, brass elbow, brass connector, and street tee.
• RK-RMB (Rate-Master® B): Includes a Regulator assembly, 3/8" tubing – copper, 1/4" NPT X 1-1/2" Nipple-brass, two 1/4" NPT X 3/8" tube comp. fittings, and a 1/4" NPT Street Tee – Brass.

Installation notes indicate that users should use a small amount of joint compound or teflon tape on threads and avoid excessive tightening to prevent damage. It may be necessary to adjust the tubing by pulling legs apart slightly or screwing the regulator in or out one turn during installation.

Key Product Differences

The series distinguishes between kits for Rate-Master® (RMA, RMB) and Visi-Float® (VFA, VFB) flowmeters. Dimensional differences exist across the models:

• RKA-RMA: Overall dimensions A: 5-11/16", B: 2-1/8", C: 3-9/16".
• RKA-VFA: Overall dimensions A: 8-1/2", B: 2-1/16", C: 3-9/16".
• RK-RMB: Overall dimensions A: 8-1/2", B: 2-13/16", C: 3-15/16".
• RK-VFB: Overall dimensions A: 7-3/4", B: 2-1/16", C: 3-9/16".

All models share a width of 3 inches and utilize 1/4 NPT connections. Replacement parts are ordered by stating the model number of the flowmeter kit and specific part numbers, such as Part No. 3 for the regulator assembly.