The World's First microwave-assisted Flow Rate Valve for Ferrous and Non-Ferrous Media!

µWValve-15: Range 0-15 kg/min (ferrous) µWValve-07: Range 0-7 kg/min (non-ferrous)

Figure 1

Figure 2

Figure 3

Closed loop system using PA FlowMaster and PA microwaveValve

Easy plug & play system with a minimum of cables. Up to 4 valves can be connected in serial order

One of the most important control parameters for the shot peening process is mass flow rate. In order to achieve precise dosing of peening media to achieve the right kinetic energy and hence the residual stress in the component, most conventional shot peening machines use contactable sensors to detect mass flow rate. One of the problems faced by industry is that prolonged contact of media with the sensor would result in the wear and tear of the sensing head. Secondly, most media dosage units that are available in the market can only detect either ferrous or non-ferrous media independently.
Product Development Objective

It had to be a one-stop solution for monitoring and controlling both ferrous and non-ferrous media flow for shot peening machinery. The proposed media dosage unit meets the requirements of SAE AMS 2430 & AMS 2432 through testing.

Product Details of Microwave Technology

The flow rate valve creates a homogenous measurement field of the media flow and thereby detects and controls the media flow rate.

This technology is based upon the Doppler Effect; wherein on encountering an object, the microwaves will either be reflected, absorbed or pass through the object, the amount of which will depend on the composition of the object encountered.

The microwave sensor in the dosage unit incorporates a transceiver that is positioned into the material process pipe as shown in Figure 1. If a particle is moving into the field as shown in Figure 2, this will be accounted for and evaluated. The corresponding signal of the microwave sensor will then be evaluated to give a corresponding mass flow output as shown in Figure 3.

µWValve Models and Features

Presently there are two types of microwaveValve models on the market. The µWValve-15 with a range 0-15 kg/min for ferrous media, and the µWValve-07 with a range of 0-7 kg/min for non-ferrous applications. The easy plug & play concept is designed to be implemented in new machines or as a retrofit for existing machines.

Summary of Features:
• ±5% full-scale accuracy
• Meets SAE AMS 2430 and AMS 2432 specifications
• Digital signal: no data transmission lost
• Able to include 4 media calibrations in one valve
• Includes a 5-meter length wire 
• 24V DC
• CE compliant
• Patent pending


The unit is a precision control valve that regulates media in pressure or gravity feed peening and blasting machines. The valve has a built-in flow sensor that is able to provide closed loop feedback to the shot flow processor. The shot flow processor is a high-end processing device that regulates the media flow rate with auto-tune technology.

When connected to the PA FlowMaster, the configuration of the PA microwaveValve can be retrieved and manipulated by the users for their desired applications. The equipment can be operated in two modes – manual or auto. Manual mode allows users to control the valve with constant flow rate, while auto mode enables auto-tune technology to regulate the flow rate. 

The PA microwaveValve complies with SAE AMS 2430, AMS 2432 and other technical requirements. It only needs a 24V DC power supply to operate.


The new microwaveValve, with its non-contact based sensing mechanism, its full scale accuracy according to AMS specification combined with the compatibility with the existing PA FlowMaster that can control up to four valves, is a milestone achievement within the shot peening and blasting industry. It will lead to new applications that have not been possible before.


Peening Accessories GmbH
Tel. +41.44.8312644 (Switzerland)

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