Complete Instrument Hook-Up Fittings Solutions by Samvay Fluid Tekniks Inc.

Product photos

In process instrumentation, the “hook-up” refers to the complete assembly of components that connect a process instrument (transmitter, gauge, switch, etc.) to the process piping or vessel. This critical interface determines the accuracy, reliability, and longevity of your measurements. Samvay Fluid Tekniks Inc. offers a comprehensive range of instrument hook-up fittings, from the root valve at the process connection to the final instrument connection, all engineered to work together as a cohesive system.

What Are Instrument Hook-Up Fittings?

Instrument hook-up fittings encompass all components between the process tapping point and the instrument. A complete hook-up typically includes:

Why Choose Samvay for Hook-Up Fittings?

Single Root Valves for Instrument Isolation

The root valve is the first isolation point from the process. Installed directly at the process tapping on pipes or vessels, it provides the ability to isolate the entire instrument hook-up for maintenance, calibration, or replacement without shutting down the process.

Product Overview

Single root valves are available in multiple configurations to suit different process conditions, mounting requirements, and operator preferences. They serve as the primary safety isolation point and must be robust, reliable, and accessible.

Types of Root Valves

Technical Specifications

Single Root Valve Range

By Connection Type:

By Size:

Industry Applications

Double Block & Bleed Root Valves for Critical Isolation

For applications requiring positive isolation, such as hazardous fluids, high-pressure systems, or when maintenance must be performed safely, double block and bleed (DBB) root valves provide two independent isolation barriers with a vent/bleed between them.

Product Overview

A double block and bleed valve consists of two isolation valves (blocks) in series with a bleed valve between them. When both block valves are closed, the bleed valve can be opened to verify that no pressure is trapped between them, confirming complete isolation from the process.

Key Features & Benefits

Technical Specifications

Available Configurations

Industry Applications

2-Valve Instrument Manifolds for DP Transmitters

The 2-valve manifold is the most common configuration for differential pressure (DP) transmitters. It provides two block valves, one for the high-pressure side and one for the low-pressure side, allowing isolation of the transmitter from the process.

Product Overview

A 2-valve manifold mounts directly to the DP transmitter or is installed in the impulse lines. With both block valves closed, the transmitter can be removed for maintenance. However, a 2-valve manifold does not provide equalization between high and low sides, so it is typically used for liquid service where the equalization function is not critical.

Key Features

Technical Specifications

2-Valve Manifold Types

Installation Options

Direct Mounting (Rosemount Compatible):

• Standard bolt pattern fits most DP transmitters
• Gasket included for leak-free seal
• No additional piping required

Inline Mounting:

• 1/4″ or 1/2″ NPT connections
• Can be bracket-mounted
• Flexible installation locations

3-Valve Instrument Manifolds with Equalization

The 3-valve manifold is the most versatile and widely used configuration for differential pressure transmitters. It adds an equalization valve between the high and low pressure sides, allowing the transmitter to be zeroed and calibrated in place without removing it from service.

Product Overview

A 3-valve manifold consists of:

• High-Pressure Block Valve, Isolates HP side
• Low-Pressure Block Valve, Isolates LP side
• Equalization Valve, Connects HP and LP sides

The equalization valve allows the two sides of the transmitter to be connected together, equalizing pressure. This is essential for:

• Zero checks and calibration
• Steam service (to protect against thermal shock)
• Gas service (to prevent over-range during start-up)

Key Features

Technical Specifications

3-Valve Manifold Types

By Mounting:

By Valve Arrangement:

By Features:

Standard Bolt Patterns (Direct Mount)

Industry Applications

5-Valve Instrument Manifolds for Maximum Control

For applications requiring the highest level of control and flexibility, such as custody transfer, critical safety systems, or when frequent calibration is needed, the 5-valve manifold adds vent/calibration valves to the standard 3-valve configuration.

Product Overview

A 5-valve manifold includes:

• High-Pressure Block Valve
• Low-Pressure Block Valve
• Equalization Valve
• High-Pressure Vent/Calibration Valve
• Low-Pressure Vent/Calibration Valve

The additional vent valves allow:

• Venting of trapped pressure on either side
• Connection of calibration equipment without disturbing process connections
• Drainage of condensate from each side
• Safe bleeding before disconnection

Key Features

Technical Specifications

5-Valve Manifold Types

Double Compression Tube Fittings for Instrumentation

The backbone of any instrument hook-up system is the tube fittings that connect all components together. Samvay’s double compression tube fittings use a two-ferrule system that provides independent sealing and gripping functions for reliable, leak-free connections.

Product Overview

Double compression (also called two-ferrule) tube fittings are the industry standard for instrumentation applications. The design separates the sealing and gripping functions:

• Front Ferrule: Seals on the tube and fitting body (creates leak-tight metal-to-metal seal)
• Back Ferrule: Grips the tube securely (acts as a spring, absorbs vibration)

This independent action ensures:

• No tube rotation during make-up (prevents scoring)
• Excellent vibration resistance
• Multiple remakes without performance loss
• Consistent, reliable sealing

Key Features

Technical Specifications

Complete Tube Fitting Range

Connectors:

Elbows & Tees:

Special Purpose:

Tube Fitting Configurations

Tube to Pipe Adapters

Connect tubing to threaded pipe connections with Samvay’s tube-to-pipe adapters. These transition fittings combine a double compression tube fitting on one end with standard NPT or BSP pipe threads on the other.

Technical Specifications

Available Configurations

Stainless Steel Instrumentation Tubing

The connecting lines between components are critical to system performance. Samvay offers a full range of stainless steel instrumentation tubing in seamless and welded construction, annealed for easy bending and flaring.

Technical Specifications

Tubing Selection Guide

Test & Calibration Valves

For systems requiring frequent calibration or sample points, dedicated test and calibration valves provide safe, convenient access without disturbing the main hook-up.

Product Range

Appendix: Hook-Up Components Quick Reference Table