What is the purpose of this article?
To provide guidelines on how the Rheonics SRV inline viscometer or SRD density and viscosity meter can retrofit the VAF ViscoSense line of viscosity and density sensors.
What products are involved?
SRV - Inline Viscosity Meter and SRD - Inline Density and Viscosity meter


1. Introduction

Rheonics sensors are used in multiple industrial applications to measure the viscosity and/or density of fluids, enabling highly accurate tracking and tight control of the fluid.

The Rheonics SRV sensor measures viscosity and temperature inline, while the Rheonics SRD sensor measures density in addition to viscosity and temperature.

The sensor probes are compact, light, hermetically sealed, and factory-calibrated, so they don’t need re-calibration during its operational lifetime.

Rheonics sensors use a balanced torsional resonator (BTR) as sensing technology, which vibrates torsionally and is connected to the outside world at a node. The BTR technology patented by Rheonics offers a significant advantage over competitors in the market, as it allows the SR-sensors to be compact, lightweight, and resistant to external vibrations. Review Rheonics sensor operating principle.



2. Retrofit

Users may need to replace a viscometer or density meter in line due to malfunction, lack of spare parts, or to simply try out Rheonics sensors and the BTR technology advantages. 

In those cases, the user most likely has an existing installation point from the former sensor that he may want to re use to install the Rheonics Type-SR sensor. The SRV and SRD favor retrofit installations due to the modular design of the probe. Rheonics offers different probe variants, these are flush, short and long insertion sensors, with all process connections available while ensuring consistency of performance across all variants.


What needs to be verified for good installation of the SRV and SRD?

The SRV and SRD probes have a sensing area that should be free of obstructions and deposits. These areas should be immersed in the fluid of interest. Review this article for more information: Installation Guidelines for inline process SRV viscometer and SRD density and viscosity meter.

By selecting the correct insertion length “A” and process connection “B“, Rheonics Type-SR sensors can be ordered to retrofit almost all existing installations, while having the sensing area correctly placed. Figure 1 shows the SRV-X4 (Flush Tri-Clamp),  -X2 (Short threaded) and -X5 (Long insertion flanged), all with customizable process connection.


Rheonics favors open standards and these also provide a way for customer to order an alternative sensor when they plan to replace Rheonics ones.

Figure 1: Rheonics SRV sensor versatility on design.


3. VAF Instruments

VAF Instruments is a company mainly focused on the maritime industry and builts sensors and solutions specially suited for that area. 


VAF ViscoSense: 

The ViscoSense, viscosity and density meters, is one of VAF product lines for inline measurement and process control of ship’s fuel to achieve combustion efficiency. The ViscoSense3 is a viscosity and temperature sensor and the ViscoSense3D adds density as a third reading. Rheonics offers the SRV and SRD sensors for potential retrofits of the VAF units.

Table 1: Rheonics and VAF Instrument viscometer and density meters 

VAF Instrument
Rheonics sensor for retrofit
ViscoSense 3
Rheonics viscometer SRV
ViscoSense 3D
Rheonics density and viscosity meter SRD

 Figure 2: Rheonics SRV and VAF ViscoSense 3 comparison - mm [in]. Download drawing.  


Installation of the VAF ViscoSense sensors require a ductile iron sensor housing specially designed for marine applications. The ViscoSense housing varies in sizes and it is shown in Figure 3 and 4. The sensor probe is threaded in the housing which has flanges as connection to the process.


Figure 3: ViscoSense sensor and housing [1].

Figure 4: ViscoSense sensor and housing detailed [1].


Rheonics sensors don’t need the use of a factory designed housing for operation, but the sensor can be ordered to retrofit the standard VAF housing if this housing is to be reused..

See Figure 5 as an example. The Rheonics SRV viscometer can be ordered to replace a VAF probe and use the existing housing. Depending on the housing size and fluid type, the required SRV probe for VAF retrofit is a short probe with custom threaded connection (SRV-X1-XXX). For specific cases, where long insertion is required, -a slimline long insertion probe with custom connection (SRV-X6) can be used. 

Figure 5: Rheonics SRV viscometer retrofit for VAF ViscoSense - mm [in]. Download drawing. 

Figure 6: Rheonics SRD density and viscosity meter retrofit for VAF ViscoSense - mm [in]. Download drawing. 


VAF ViscoSense in Viscotherm housing

Viscotherm is an older viscosity measuring system from VAF. The Viscotherm housing (Figure 6) now enables users to retrofit the original Viscotherm system entirely. Once again, Rheonics Type-SR sensors can be mounted in these housings with the correct configuration as in Figure 7.

Figure 7: Viscosense on Viscotherm housing (VAF order code: 0401-0816) [2]. 

Figure 8: Rheonics SRVviscometer retrofit for VAF ViscoSense - mm [in]. Download drawing.


Figure 9: Rheonics SRD density and viscosity meter retrofit for VAF ViscoSense - mm [in]. Download drawing.


4. How to order a Rheonics Type-SR sensor for retrofit?


To get a quote for VAF viscosense, do the following:

a. Use the online RFQ pages for SRV inline viscometer and SRD viscosity and density meter.

b. Select the operating conditions (temperature and pressure rating ) and sensor specifications (electronics, measurement range, calibration, etc.)

c. For process connections, select X1 - custom thread. Use the fillable box below the process connection options to write "VAF retrofit required". Specify the thread type required, if different to M40x1.5. 

d. If possible, send installation pictures or drawings of the sensor to be replaced to [email protected]


Note: Rheonics sensors are suitable for retrofits but care should be taken to comply with minimum installation requirements for the sensing element to ensure reproducible and repeatable readings. These can be reviewed in any other article for SRV and SRD.


Contact the technical sales team at [email protected] or Technical support team at [email protected] if needed to help you get the correct retrofit.


Disclaimer

Pictures, photos, and images used are for illustration purposes and do not constitute any warranty or assertions on the suitability of use and should not be construed as an explicit or implicit recommendation or endorsement. All illustrations are given proper credit from our source of access and by their use here we do not specify or establish any copyright which belongs and stays unaffected with the existing copyright holder of that material.


References

[1]: Viscosense 3

[2]: Retrofitting Viscotherm to Viscosense


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