What Products are Involved?
SRV - Inline Viscosity Meter and SRD - Inline Density and Viscosity Meter and relevant installation accessories

What is the purpose of this article?
To give guidance on the installation of Type-SR sensors in sweep elbows

TABLE OF CONTENTS

• Introduction
• Installation guidelines for Type-SR sensors in sweep elbows
  • Sweep elbows with ascending fluid
    • Installations in the bottom elbow
    • Installations in the top elbow
  • Sweep elbows with descending fluid
    • Installations in the bottom elbow
    • Installations in the top elbow
    • Installation in sweep elbows with intermittent descending fluid
  • Sweep elbows with inlets and outlets at the same elevation.
  • Elbolets and flanges

Introduction

Sweep elbows are a crucial component in industrial piping systems, designed to provide smooth, gradual changes in the direction of fluid flow. Unlike standard elbows, which feature sharp angles, sweep elbows are characterized by a wider curve, minimizing turbulence and pressure drops. This design helps improve flow efficiency and reduces the risk of erosion and wear on pipes. Commonly used across all industries, sweep elbows are favored for their ability to handle high-flow conditions and ensure long-term performance in complex piping networks.

Figure 1: Sweep Elbows installed in an industrial application.

This article will focus on sweep elbows and how Rheonics Type-SR sensors can be installed in them. For the purpose of clarity, we will be referring to “bottom” and “top” elbows, which can be better understood in the Figure below.

Installation guidelines for Type-SR sensors in sweep elbows

When installing Type-SR sensors in sweep elbows, care must be taken to ensure a proper selection of the insertion length such that the sensing element is placed past the straight section of the bend, ensuring it is fully submerged in the fluid. While this is highly recommended, it may not always be achievable, especially for lines with big diameters such as 12” or above. In these cases, the insertion length must be long enough to ensure the sensing element is fully submerged in the fluid.

Figure 3: Installation showing adequate insertion length

The process connection of the sensor probe is ultimately left to convenience and/or the requirements set by the system (hygienic connections, pressure rating, standardization of ports, etc.)

Additionally, the fluid flow direction is a key factor for selecting the best installation point. Below we explore some details on how this can change the recommended point of installation. In general, it is recommended that the sensor is installed so that the flow of fluid impacts the sensing element first.

Sweep elbows with ascending fluid

A piping system that requires the increase in elevation of fluid may employ the use of sweep elbows. In these cases, Type-SR sensor probes can be installed in either the bottom or top elbow based on process conditions and space limitations.

Installations in the bottom elbow

If an installation in the bottom elbow of an ascending fluid system is possible, it is recommended to install the sensor here. As long as there is fluid before the outlet of the elbow, the sensor will be completely submerged in fluid. In case fluid flow is intermittent, gravity will ensure the sensor remains submerged. Additionally, this position allows for the sensor to be cleaned by the fluid once the operation is resumed.

Figure 4: Installation of an SRD sensor probe in a bottom elbow with ascending fluid

Table 1: Installation examples for bottom elbows

Installations in the top elbow

In case installation is not possible in the bottom elbow, an installation in the top elbow is feasible. This style of installation is less likely to form deposits due to gravity, if the sensor is exposed to inconsistent flow the quality of the readings may be affected. Finally, for large pipes, it is important to select an insertion length that places the sensing element after the bottom of the horizontal pipe, ensuring that it will be fully submerged during operation, An example of this can be seen in the image below.

Table 2: Installation examples for top elbows 

Sweep elbows with descending fluid

A piping system that requires a decrease in elevation of fluid may employ the use of sweep elbows. In these cases, Type-SR sensor probes can be installed in either the bottom or top elbow based on process conditions and space limitations.

In general, installation in elbows with descending fluids is not recommended unless the line is known to be full of fluid. These lines are particular as gravity will move fluid downwards and away from the sensing element. Below are examples of possible installations when the line is full of fluid.

Installations in the bottom elbow

Installation in the bottom elbow for descending fluid is rarely recommended, as it is highly dependent on the system being full of fluid. This installation has the additional drawback of being prone to the creation of deposits around the standpipe. While these may not directly affect the readings, they could have a negative impact on the fluid, creating possible cross-contamination and being generally harder to clean.

Installations in the top elbow

If the system is known to be full of fluid, installation is preferred in the top elbow. This is due to the fact that it has the added benefit of reducing fluid stagnation around the sensor body's standpipe.

Installation in sweep elbows with intermittent descending fluid

In case the system is not consistently full of fluid, or flow is known to be intermittent, an installation as seen below can be performed. While the sensing element is not opposing the flow of fluid, it is the most viable alternative to ensure that the sensing element operates in a region of the pipe where fluid is known to be present.

Sweep elbows with inlets and outlets at the same elevation.

In case sweep elbows are used to change the direction of a pipe across the horizontal plane, the sensor should be installed such that the sensing element is opposing the flow of the fluid. Installation in these systems is recommended as long as the fluid level is known to fully cover the sensing element.

Elbolets and flanges

In general, elbolets and flanges installed must ensure the port sits concentrically to the pipe, which will place the sensing element of the probe in the center of the fluid flow. 

Currently, Rheonics does not provide any elbolets or flanges for elbow installations. The acquisition and installation of these are left to the end customer and must be selected to comply with process requirements (pressure, material selection, etc.).

In case a threaded process connection is selected, a threaded pipe can be machined and welded to the elbow. The same can be said about flanged ports as long as the standpipe of the port allows the sensing element to pass the straight section after the bend. Our Type-SR X5 (SRV/SRD) variant can come equipped with a 1.25” NPT male thread or with a flange of your choice. Click here for the list of compatible flanges.