What is the purpose of this article?
To give guidelines on the compatibility of flange connections with Rheonics Type-SR process density meter and viscometer available in short, slimline, long insertion, and hygienic long insertion variants.
What products are involved?
Rheonics SRV viscometer, and SRD density and viscosity meter.



1. Introduction

Flanges

Flanges are used as industrial connections in pipes, tanks, instruments, peripherals, etc. Flanges vary according to regional norms or standards (like ANSI, DIN, JIS), and by size, pressure rating, and face type. Flange connections are composed of two flanges, bolts, nuts, and, most of the time, a seal. 

Some regional norms for flanges are: 

  • ISO 7005-1: Pipe flanges - Steel flanges for industrial and general service piping systems
  • ANSI ASME B16.5: North American standard applicable for flanges.
  • DIN 2527: German standard applicable for flanges. 
  • BS/EN 1092: British standard applicable for flanges.
  • JIS B2220: Japanese Industrial Standards applicable for flanges.
  • SH/T 3406-2022: Chinese technical specifications for petrochemical steel pipe flanges.
  • GB/T9115.1-2000: Chinese standard for Welded pipes flange 
  • IS 13159: Indian standard for pipe flanges and flange fittings - Specifications.

Most flanges have markings on the outer surface that indicate the norm/standard and its technical information. Some norms have very similar dimensions between flanges but it is not recommended to install two flanges of different norms, this means they are not interchangeable.


Rheonics Type-SR sensors

Rheonics sensors Type-SR, viscometer SRV, and density and viscosity meter SRD can be configured with all flanges norm, sizes, and ratings available, either in its short probe (SRV-X2 and SRD-X2), long insertion variant (SRV-X5 and SRD-X5) or slimline probes (SRV-X6 and SRD-X6).

Figure 1: Long insertion SRV (SRV-X5) with Flange Installation


For a correct installation, the following should be considered:

  • Use matching flanges of the same norm, size, and pressure rating.
  • Consider the compatibility of the sensor’s wetted material variants with chemical fluids
  • Consider installation of seals for flanges
  • Flanges or standpipes should not cover the sensing area of the sensor probes. Sensing areas shown in the next Figure should be completely immersed in the fluid, avoiding dead zones. 

Figure 2: Rheonics SRV and SRD sensing areas



2. Compatibility table

Rheonics SRV and SRD sensors can be configured with virtually all flanges available, but some variants are better suited for some flanges due to the size, OD, ID of the matching flange, etc. The next table shows a reference for compatibility between Rheonics sensor variants and flanges under each standard.

Figure 3: Relevant dimensions in Flange installations.


From previous Figure, relevant dimensions are:

  • OD: Outer diameter of flange
  • ID: Inner diameter of matching flange and standpipe
  • T: Thickness of flanges joint
  • ST: Standpipe length, distance to the main pipe surface

Table 1: Flange’s size compatibility with Rheonics Type-SR sensors

ODIDTSTShort (SR-X2)Slimline (SR-X6)
Long insertion (SR-X5)Long Hygienic (SR-HS-X5)
Less than 100 mm (4”)
Bigger than 21 mm (0.82”)
Any*Less than 400 mm (15”)




Less than 152 mm (6”)
Bigger than 28 mm (1.1”)
Less than 25 mm (1”)
Less than 30 mm (1.2”)





Bigger than 32 mm (1.26”)
Any*Any*




Bigger than 44 mm (1.73”)
Any*Any*



Bigger than 152 mm (6”)
Bigger than 32 mm (1.26”)
Any*Any*




Bigger than 44 mm (1.73”)
Any*Any*




*For long insertion probes (-X6, -X5, and -HS-X5), the insertion length “A” should be correctly configured according to the thickness of the flange (T) and standpipe length (ST).


Notes:

  • For EHEDG-certified installations review Rheonics the installation guide for EHEDG. 
  • Consider flanges require the use of a seal. The sensor probe needs to go through the seal ID, which is generally equivalent to the “ID” dimension in the table.

3. Selecting a Flange

The selection of a flange is defined by the working or operating conditions of the process, from which the pressure rating is usually of most relevance. Next considerations should be taken:

  1. Regional norms or standards - Flange’s norms vary depending on the geographical location of installation as mentioned in Section 1: Introduction.
  2. Material compatibility - Stainless steel and carbon steel are the two most common materials for industrial flanges. For the Rheonics Type-SR sensors, the SS flanges are used which have also a great corrosion resistance level.
  3. Pressure rating - The operating pressure that the connection should handle is of most relevance when selecting the flange to use. Flanges are designed by pressure ratings (each norm can use a different pressure unit). The user should look for the needed pressure level but also consider that operating temperature and material affect the flange’s maximum pressure allowed. For example, ANSI flanges define the pressure ratings in psi, a Class 150 ANSI flange is rated to 150 psi but only under specific conditions of temperature and material.

Rheonics sensors are available with the following pressure ratings for ordering with standard process connections. All sensors are suitable for use in vacuum applications as they are hermetically sealed - select the process connection to meet your vacuum material restrictions. The standard pressure rating goes from P1 to P2 and so on to specify higher pressure ratings. Select the pressure rating that you need for your process using the RFQ form. Rheonics Type-SR and Type-DV sensors are also available for higher pressure (up to 25k psi for Type-SR and 40k psi for Type-DV) than mentioned in the table below, for these ultra-high pressure applications, contact the sales team, at [email protected], with your requirement (pressure rating, process connection, material, certification, etc).


Important: To order a Rheonics sensor for a specific working pressure, both the flange and the probe (in the RFQ form) should be rated for such pressure. Standard Rheonics sensor probes have the pressure rating defined by the -P code in the order code, e.g. P1 (15 bar), P2 (70 bar), and so on.


Table 2: Maximum Pressure rating available for Rheonics Type-SR sensor variants compatible with flanges

Sensor VariantMaximum pressure rating availableComment
Short (SR-X2)
500 bar (7500 psi)
P5 pressure configuration
Slimline (SR-X6)
500 bar (7500 psi)
P5 pressure configuration
Long (SR-X5)
100 bar (1500 psi)

Should be requested upon order.

For long insertion probes with higher pressure ratings, contact Rheonics.

SR-HS Long (SR-HS-X5)
100 bar (1500 psi)
SR-HP
1700 bar (25k psi)
Contact Rheonics.
Special solutions

700 bar (10 000 psi)

500 bar (7500 psi)

SRV-SDP: Sand detector probe 

SRD-API: API Hubs 


4. Nominal size - This varies according to the size of the line or standpipe that is needed. Refer to the flange norm for sizes available.

5. Face type - Most of the flange norms have three face types: Raised Face (RF), Flat Face (FF), and Ring-Type Joint (RTJ). Each has recommended application cases. The RF and RTJ are usually used for low, medium, and high-pressure ratings since they concentrate the pressure in a specific area of the flange. The FF face distributes pressure in all the flat faces and is not recommended for high-pressure conditions (approx. higher than 600 psi).

6. Seal type - For each face type there are specific seal types available. Material, size, and type should be defined. Rheonics Type-SR probes should fit through the seal ID, see the minimum ID requirement in Table 1.


4. Flanges for Rheonics Sensors

As mentioned before, Rheonics sensors SRV and SRD can be ordered with any flange for installation. However, some flange norms and sizes are more common than others and are usually kept in stock or sourced directly by Rheonics, leading to a faster delivery of the sensors. Whereas other flanges can be categorized as “custom” and may even need the client to send the flanges to Rheonics for production of sensors, this leads to a longer delivery time.

The next table shows the most commonly used flanges by Rheonics, these are generally kept in stock or can be sourced locally by Rheonics so the sensor can have a fast delivery time.


Table 3: Common flanges for Rheonics Sensors

NormSpecificationOptions
ANSI ASME B16.5
Sizes1”, 1.5”, 2”, 3”, 4”, 6”, 8” and 16”
Pressure rating150lb, 300lb
Face typeRF
DIN 2527DN25, 40, 50, 80, 100, 150, 200, 400
PN6, 10, 16, 25, 40 PN
Face typeRF
ISO 7005-1DN25, 40, 50, 80, 100, 150, 200, 400
PNPN6, PN16, PN25, PN40, PN100

The next table lists other flange norms that Rheonics is familiar with, but are not frequently used, which means that delivery lead times can increase. Clients can order a similar ANSI or DIN flange or may need to send the specific flange directly to Rheonics.


Table 4: Less common flanges for Rheonics Sensors

NormSpecificationOptions
UK - BS/EN 1092DN25, 40, 50, 80, 100
PNPN6, PN10, PN16, PN25, PN40, PN100
Face typeRF
Japan - JIS B2220DN25, 40, 50, 80, 100
PN5k, 10k, 16k, 20k
Face typeRF
China - SH/T 3406-2022 DN25, 40, 50, 80, 100
Class150lb, 300lb
India - IS 13159
DN25, 40, 50, 80, 100
PNPN20, PN50, PN100, PN150

5. Ordering Rheonics SRV process viscometer and SRD density meter with Flange

To order a Rheonics product, the user should go through  the RFQ form page online.

Codes relevant to flange and pressure configuration are shown below:

Table 5: Order codes for SRV and SRD flange sensors.

How to order Rheonics Type-SR sensor with flange?

1Rheonics SR- Type sensor

SRV: Inline Viscometer

SRD: Inline Density and Viscosity meter

SRV Viscometer online RFQ
SRD Density meter and viscosity meter RFQ
2

Pressure Rating

Define the pressure rating for the sensor probe.

For higher pressure ratings or specific solutions (SR-HP, SRV-SDP, SRD-API, etc.) contact Rheonics Sales Team directly at [email protected]

3

Process Connection Configuration

Define the process connection from the options shown*. Probe variants compatible with flanges are:

  • -X2: Short variant. Define flange with norm, size, pressure rating, etc.
  • -X5: Long insertion variant. Define flange with norm, size, pressure rating, etc.
  • -X6: Slimline long insertion variant. Define flange with norm, size, pressure rating, etc.

*Rheonics can keep adding new process connection variants.

4

Insertion Depth - “A” - If applicable

Only applicable for the -X5 and -X6.

The insertion length should be defined, this is the distance between the sensor tip and the flange. Probe wetted zone.

5

Process Connection "B" 

Process connection should be defined by the user for all flanges with norm, size, pressure rating, etc. 

Rheonics will then create the corresponding flange’s code.

Prefix “B” is omitted for -X2 sensors, only using flange’s code.

Examples:

  • A20A: ANSI Flange 2” 150lb RF
  • D50CR: DIN Flange DN50 PN16 RF

If a hygienic sensor probe is needed, select the certification required - EHEDG or 3A. Options can be found in the RFQ.
Complete the RFQ form with missing details (viscosity and/or density range, calibration accuracy, temperature rating, etc.), submit the form, and the Sales Team will contact you soon.

Related Articles

1. Rheonics Viscometer Short Custom Flange: SRV-X2

2. Rheonics Viscometer Long Insertion Flange - SRV-X5

3. Rheonics Viscometer Slimline Flange - SRV-X6.

3. Rheonics Density meter Short Custom Flange: SRD-X2

4. Rheonics Density meter Long Insertion Flange - SRD-X5

5. Rheonics Density meter Slimline Flange - SRD-X6.