What is the purpose of this article?
To provide instructions for the customer interface of flange and extension tube for the assembly and installation of Rheonics SDP-X9-HPWA

What products are involved?
Rheonics SDP Sand Level Detection Probe

Introduction

Rheonics SDP is a Sand Level Detection Probe designed to sustain the most harsh and high-pressure conditions in oil and gas extraction lines, upstream, midstream, and downstream with a pressure rating possible up to 20k psi (1400 bar). Rheonics SDP is installed in desanders, pipelines, or any equipment where either sand switch detection or sand erosion measurement is needed for proper sand removal or managament automation.

Rheonics offers the SDP in two variants: The SDP-X9-HPWA, which includes the probe, protecting cage and a High-Pressure (HPWA-SDP) welding adapter, and the SDP-X9-CUS, a fully assembled design that adds an extension tube or sleeve and a flange for mounting. The -HPWA variant enables clients to independently source the tube and flange, and weld them on the HP adapter, following Rheonics guidelines.

Review SDP custom drawing.

Note: Rheonics SDP is offered in 316L material (1.4404/1.4435).

Rheonics SDP-X9-HPWA	Rheonics SDP-X9-CUS-Axxx-Bxxx
SDP Probe with HP Weld Adapter (HPWA-SDP) and Protection Cage	Adds custom extension tube and flange, with optional connector cover and end, supplied by Rheonics

Mechanical Interfaces

In the SDP-X9-HPWA variant, Rheonics offers the SDP probe with the HP welding adapter (HPWA), as well as the cable and electronics. This is labeled as Rheonics SDP in next image. Customers source locally the extenstion tube and custom flange, while the connector cover is offered by Rheonics if needed.

Note: Flange and extension tube must be of a material compatible with 316L for welding.

The connector cover serves as protection to a cable connector between the SDP probe and electronics, enabling an easy disconnection in place. If the connector cover is not used, it is recommended to place a cable gland for the cable exit in the flange.

Figure 1: Rheonics SDP assembly example

Custom Extension Tube

The extension tube defines how immersed is the SDP sensing element (sensing element has a 46 mm or 1.8” length) in the equipment i.e. desander, tank or pipeline. Generally, is recommended to keep the sensing element in the middle of the equipment and away from walls. Consider the following:

Extension tube material should be 316L. Its length is defined by client. It should be rated for desired pressure.
Minimum inner diameter required is 16 mm for cable to go through. If the cable connector is needed to go through the tube, then this diameter should be 19 mm.
The tube end outer diameter must be 31.8 mm with given tolerances. Each tube end is either inserted in the HPWA adapter or the custom flange. For correct insertion in the HPWA, 12 mm of length in this 31.8mm diameter tube end is recommended.

Figure 2: Extension tube interface drawing

Custom Flange

The flange must be rated for the desired pressure rating, material should be compatible for welding with extension tube (316L). Two interfaces are given for the flange. First one is for the welding to the previously detailed extenstion tube. Second interface is for the optional connector cover supplied by Rheonics.

Note: Flange norm and size is selected by customer. Pressure rating should be compatible with operating condition.

Flange-Tube Interface

In next Figure the Flange-Tube interface is the left side of the flanged, detailed in section C in drawing. Consider next guidelines:

Custom flange is defined by client. It should be rated for desired pressure.
Relevant dimension here is the 31.8 mm with given tolerances in order to insert and weld the extension tube. The
The 52 mm diameter in the flange is a recommended clearance for welding but can vary in each assembly.
A bore through hole of at least 16 mm is required for the sensor cable.

Flange-Connector Cover Interface

In next Figure the Flange-Connector Cover interface is the right side of the flanged, detailed in section A and B in drawing. Consider next guidelines:

The use of the Connector Cover is optional.
An NPT 1/2” thread on the flange back side is used to place a cable gland, delivered by Rheonics if the Connector Cover is ordered. This NPT thread is recommended even if the Connector Cover is not used, as it serves for the position of the cable gland end.
A total of 4 equidistant M5 8 mm length threaded holes with a pitch circle diameter (PCD) of 85.5 mm diameter are needed to fix the Connector Cover in the flange.