What products are involved?
SRV - Inline Viscosity Meter

What is the purpose of this article?
To give an overview of the flush version of the SRV sensor (SRV-X4), uses and installation options for hygienic and sanitary applications.

1. Introduction

SRV is Rheonics sensor for inline viscosity measurement (viscometer). Read more on SRV here.

The flush version of the SRV inline viscometer, shown in Figure 1 and 2 with a Tri-Clamp connection, is used to mount the viscometer in a flush installation. Flush means that the dead zones are partially or completely removed, depending on the type of installation or accessory used for installation. The probe's hygienic design and possible hygienic certification, along with the removal of dead zones, make the probe easier to clean and disinfect with standard procedures (e.g. Clean in Place - CIP). This design is also useful for small pipes and process connections smaller (e.g. Tri-Clamp DN 20) than those available with the standard short or long SRV. Review these other variants here.

Following the specified hygienic considerations, a flush installation can considerably reduce or eliminate the possibility of plugging, deposits and dead zones that can cause systematic errors in the viscosity readings of the SRV.

Using an SRV-X4 variant is common for specific Rheonics integrated solutions like CoaguTrack for cheese coagulation. 

1.1 Compatible process connections 

Rheonics SRV flush probe is available with different process connections, some suitable norms are: 

• DIN 11853-1/2/3 min DN20
• DIN11864-1/2/3 min DN20
• DIN 11851 min DN20
• ISO 2852, DIN 32676, BS 4825 Part 3 in combination with Tri-Clamp seals
• ISO 2853, BS 48525 Part 4 in combination with T-seals
• Varinline® type T and P with EPDM O-Ring in sizes B,F,N,G

All process connections mentioned above can be ordered with a hygienic certification, EHEDG and/or 3-A. Contact Rheonics Support Team for more information.

Figure 1: SRV-X4-15T Flush Viscometer

Figure 2: SRV-X4 Flush probe dimensions

For the latest CAD models visit Rheonics Type-SR Tri-Clamp page.

2. Hygienic certifications for Rheonics SRV-X4

SRV EHEDG documentation
EHEDG Certificate for SRV	EHEDG Installation guideline

SRV 3-A certification

3-A Certificate for SRV

For the latest sensor certifications visit Rheonics Certificates Page.

3. Installation considerations

Key recommendations and concepts about the installation of the SRV sensor are detailed in other articles and apply for the Flush sensors. It is important to verify that the sensing area, shown in Figure 3, is always immersed in fluid and any stagnant zones should be avoided. Stagnant zones are defined as any space, inside the sensing area, where fluid transport is insufficient leading to immobile fluid, as well as possible accumulation of solids and deposits, or unwanted material like air.

The installation main considerations are labeled in the next drawing. Flush sensors have the sensing element right after the connection, so dead zones must be avoided at all cost (i.e. long standpipes are clearly ruled out).

Figure 3: SRV-Flush installation principles.

4. Installation examples

Some suitable process connections for the SRV flush sensor are mentioned in section 1. Installation will depend on the type of adapter used. Rheonics offers a collection of accessories for installation with flush sensors. These accessories and some other well-known installation cases are shown below.

4.1 Rheonics adapters

a. Flush Tri-Clamp adapter

This Tri-Clamp connection is a common solution for wall or bottom tank installations. It uses a flush weld-on adapter that Rheonics can provide.

Flush SR-sensors need special attention at installation to ensure good performance. It’s short insertion depth is benefitial for small spaces but a good exposure to fluid is needed.

Order codes from third parties in table above are indicated for the Rheonics SRV 1.5” Tri-Clamp as examples for next image. Other flush flanges can be used, varying in length and size if sensor Tri-Clamp size changes.

Figure 4. Flush installation example with standard TC flush flange

Figure 5. Exploded view of assembly example with TC flush flange

b. IFC-V40 - Inline flow cell DN40.

This solution allows a perpendicular installation of the SRV sensor probe in a straight DN40 or 1.5” line. This installation requires a Varinline N machined plug provided by Rheonics (PLG-VNM) as the probe connection and the blind plug, as shown in Figure 6.

The Varinline DN40 is currently the smallest GEA Housing compatible with the Rheonics SRV. If smaller housings are required contact Rheonics Support Team.

Figure 6: Flush installation drawing of SRV in DN40 Varinline Housing

4.2 Other installation options

a. Varinline DN50 or bigger

The SRV can be installed in a Varinline housing equal or bigger than DN50 with standard plugs.

The design of the Varinline housing ensures no dead zones around the sensor, leading to good flow around the sensing element.

Figure 7: Flush installation drawing of SRV in DN50 Varinline Housing

Note

The SRV has a flush, short and long insertion variants. All have a compatible hygienic design and are EHEDG certified. In this article, focus is on the flush version, but additional hygienic installations are possible with short probe variants, like the SRV-X1-12G mounted on the HAW-12G-OTK2 adapter, and other options. The long insertion pobe design has a unique article here. 

Disclaimer

References

[1]: https://rheonics.com/resources/certificates/

[2]: https://www.buerkert.ch/de/produkte/733905?utm_source=DataSheet-BBS07&utm_medium=Text-Link&utm_campaign=Article-Link&utm_content=733905

[3]: https://www.aseptconn.ch/en/aseptic-connections/novaseptic-tank-connections-na-connect/welding-flange-na-connect-sms-3008

[4]: https://www.gea.com/en/products/pumps-valves-flow-components/valves-components-hygienic-liquid-processing/inline-technology/varinline-pocket-free-instruments.jsp