Overview

This document provides technical specifications, application guidelines, and ordering information for Riels Instruments' pressure switches, specifically the RIBCD series. It includes details on product features, performance parameters, construction materials, and options for customization.

Product Description and Features

• Type: Pressure switches with differential setpoints (example given: D…H-type with 1 bar differential setpoint).
• Operating Principle: Differential pressure setpoint changes with static pressure variations; example calculation provided.
• Protection: Weatherproof to IP66 (EN 60529), equivalent to NEMA 4X.
• Construction: Cast aluminum enclosure with oven-baked powder coating in hammertone grey.
• Repeatability: Typically 0.2% of full scale.
• Units: Standard in Barg; optional units include PSI, Kg/cm², and Pa.
• Process Connection: Standard 1/4” NPT Female or BSP Female.
• Diaphragm and O-ring Materials: Various combinations depending on model (Buna N, TCP, PTFE, SS316, Viton, Teflon, EPDM).
• Wetted Parts: Multiple options available; refer to full catalogue for details.

Performance Specifications and Ranges

The document provides a detailed table of range codes, adjustable pressure ranges, differential ranges, maximum static pressure, overrange pressure, proof pressure, and typical deadband values for various models (D 359 H, D 302 L, D 304 L, etc.). Key points include:

• Ranges and deadbands are specified at 50% of maximum static pressure.
• Differential pressure sensors are sensitive to static pressure changes affecting setpoint and deadband.
• Specific notes on pressure limits and reversal capabilities for different models (e.g., D…L can withstand 1 bar differential pressure above high pressure; D…M and D…H can sustain full high and low side reversal).

An additional table estimates the influence of increasing static pressure on setpoint and deadband for different sensor types (D...L, D...M, D...H), showing variations in mBar per Bar.

Materials and Construction Details

• Enclosure Materials and Codes: Aluminum (codes C1, C3), Stainless Steel 316 (code C8), with various conduit sizes (Pg13.5, M20x1.5, 1/2” NPT F).
• Process Connection Sizes and Materials: 1/4” NPT F, 1/4” BSP F, 1/2” NPT M in aluminum or SS316.
• Diaphragm and O-ring Material Codes: Buna N, PTFE, SS316, Viton, Teflon, EPDM, welded options.

Electrical and Switch Options

• Microswitch Ratings: Various AC and DC voltage and current ratings provided, including resistive DC loads.
• Switch Types: Single Pole Double Throw (SPDT), Double Pole Double Throw (DPDT), with codes for selection.
• Environmental Protection: Options for IP67 rated enclosures.
• Special Options: Cable glands for explosion-proof (EEx) applications, stainless steel tag key rings with customizable text.

Ordering and Model Code Construction

The document outlines a stepwise procedure to build the model code by selecting:

1. Range code based on pressure range requirements.
2. Process connection type and size.
3. Enclosure type and conduit material.
4. Wetted parts materials (diaphragm and O-ring).
5. Microswitch type and electrical ratings.
6. Additional options such as environmental protection and accessories.

Notes and Recommendations

• Ranges and deadbands are influenced by static pressure; users should consider this in application design.
• Wetted parts are not guaranteed against corrosion or permeation due to varying process conditions; empirical user experience is recommended.
• Process connections compliant with NACE standards are available.
• Accessories such as pipe mount brackets and vacuum protection plates are offered.
• Riels Instruments reserves the right to modify specifications without prior notice and disclaims liability for errors or omissions.

Critical Parameters and Limitations

• Maximum static and overrange pressures vary by model and must be respected to avoid damage.
• Deadband values vary with pressure and sensor type; typical deadbands range from 0.15 to 15 bar depending on model.
• Some options are not compatible with certain models (e.g., some diaphragm materials not possible for D..H).
• Electrical ratings for DC loads are not UL listed but supported by experience and third-party testing.