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

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:

Component	Function	Located
Root Valve	Primary isolation at process connection	At process tapping
Condensate Pot / Syphon	Protect instrument from steam/high temperature	Between root valve and manifold
Instrument Manifold	Isolation, equalization, vent/drain functions	Directly at instrument
Impulse Lines / Tubing	Connect process to instrument	Between root valve and instrument
Tube Fittings	Connect tubing to valves and instruments	Throughout the system
Valves (Block, Bleed, Calibration)	Additional isolation and test points	As required
Snubbers / Pulsation Dampeners	Smooth pressure fluctuations	Before instrument
Flange Connectors	Connect tubing to flanged equipment	Interface points
Mounting Brackets	Support and secure components	For panel or pipe mounting
Accessories	Tags, guards, insulation	As required

Why Choose Samvay for Hook-Up Fittings?

Advantage	Benefit
Complete System Solution	All components from one source—perfect compatibility
Material Consistency	Same material grades throughout the system
Full Traceability	Complete documentation for quality audits
Global Standards	ASME, ISO, NACE compliant

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

Valve Type	Operation	Best Application
Needle Valve	Multi-turn, precise control	General instrumentation, throttling not typically required
Ball Valve	Quarter-turn, quick shut-off	Where fast isolation is needed, high cycle life
Gate Valve	Multi-turn, full bore	Large bore, minimum pressure drop
OS&Y Valve	Outside screw and yoke	Visible indication of valve position

Technical Specifications

Specification	Details
Material of Construction	SS316/L, SS304/L, Carbon Steel (A105), Monel, Hastelloy, Duplex
Connection Type	Male NPT/BSP, Female NPT/BSP, Socket Weld, Butt Weld
Connection Size	1/4″, 3/8″, 1/2″, 3/4″, 1″
Pressure Rating	3000 PSI (standard), 6000 PSI, 10,000 PSI (high-pressure)
Temperature Range	-65°F to 600°F (-54°C to 315°C) standard; High-temp to 1200°F available
Stem Type	Non-rotating hardened tip (needle valves); Blowout-proof stem (all)
Packing	PTFE (standard), Grafoil (high-temp), Viton, EPDM
Seat Material	Integral metal seat (standard); Soft seat optional
Handle	T-bar (standard), Wheel (optional), Locking (optional)
Testing	100% hydrostatic and pneumatic tested
Certification	EN 10204 3.1 material certification

Single Root Valve Range

By Connection Type:

Type	Configuration	Typical Use
Male x Female	Male thread into process, female outlet to tubing	Direct mount to process tapping
Male x Male	Both ends male	For welding boss or socket
Female x Female	Both ends female	Between two male connections
Socket Weld	For welding directly to pipe	Permanent installations
Butt Weld	Beveled ends for butt welding	High-pressure, high-temp

By Size:

Valve Size	Process Connection	Tube Outlet	Flow Coefficient (Cv)
1/4″	1/4″ NPT	1/4″ tube fitting	0.3-0.4
3/8″	3/8″ NPT	3/8″ tube fitting	0.6-0.8
1/2″	1/2″ NPT	1/2″ tube fitting	1.0-1.2
3/4″	3/4″ NPT	3/4″ tube fitting	1.8-2.2
1″	1″ NPT	1″ tube fitting	3.0-3.5

Industry Applications

Industry	Typical Root Valve	Special Requirements
Oil & Gas Production	1/2″ 6000 PSI needle valve	NACE MR0175
Refineries	1/2″ 3000 PSI ball valve	Fire-safe, high-temp
Chemical Plants	1/2″ 3000 PSI needle valve	Corrosion-resistant alloy
Power Generation	1/2″ 6000 PSI needle valve	High-temperature packing
Water Treatment	1/2″ 3000 PSI ball valve	NSF/ANSI 61 (optional)
Pharmaceutical	1/2″ sanitary diaphragm valve	Electropolished, USP

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

Feature	Benefit
Two Independent Isolation Valves	Redundant sealing, fail-safe isolation
Integral Bleed Valve	Verify isolation, vent trapped pressure
Compact Design	One body, multiple functions—saves space
One-Piece Construction	No leak paths between valves
Pressure Indication Port	Optional gauge port for verification

Technical Specifications

Specification	Details
Material	SS316/L, SS304/L, Carbon Steel, Duplex
Pressure Rating	3000 PSI, 6000 PSI, 10,000 PSI
Temperature	-65°F to 600°F (-54°C to 315°C)
Inlet Connection	1/2″ NPT male (to process)
Outlet Connection	1/2″ NPT female (to tubing)
Bleed Connection	1/4″ NPT female
Block Valves	Needle or ball type
Bleed Valve	Needle type (for controlled venting)
Configuration	In-line or angle pattern
Testing	100% hydrostatic, seat leakage tests

Available Configurations

Configuration	Block Valves	Bleed Location	Best For
In-line DBB	Both in line	Between blocks	Vertical pipe runs
Angle DBB	One at 90°	Between blocks	Space-limited areas
With Gauge Port	Both in line	Between blocks + gauge port	Local pressure indication
With Calibration Port	Both in line	Between blocks + test connection	Field calibration

Industry Applications

Application	Why DBB Required
Sour Gas Service	Positive isolation of H2S
High-Pressure Steam	Safety during maintenance
Toxic Chemicals	Prevent any leakage
Critical Safety Systems	Redundant isolation
Offshore Platforms	Space-saving, safety

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

Feature	Benefit
Two Block Valves	Isolate transmitter from process
Direct Mount to Transmitter	Eliminates impulse lines, reduces leak points
Compact Design	Fits in tight spaces
Bleed Ports (Optional)	Vent/drain capabilities
Multiple Connection Options	NPT, flanged, or tube extensions

Technical Specifications

Specification	Details
Material	SS316/L (standard), SS304, Carbon Steel, Duplex, Hastelloy
Pressure Rating	3000 PSI (standard), 6000 PSI, 10,000 PSI
Temperature	-65°F to 600°F (-54°C to 315°C)
Process Connections	1/4″, 1/2″ NPT/Female
Transmitter Connection	1/4″ NPT (standard), 1/2″ NPT, or as required
Bleed Connections	1/4″ NPT (optional)
Mounting	Direct mount to transmitter or inline
Valve Type	Needle valves (standard), Ball valves (optional)
Packing	PTFE (standard), Grafoil (high-temp)

2-Valve Manifold Types

Type	Description	Application
Direct Mount	Bolts directly to transmitter	Most common, eliminates impulse lines
Inline	Mounts in impulse lines	Remote mount, space constraints
With Bleeds	Includes vent/drain ports	For liquid or gas with trapping concerns
Flanged	Flanged process connections	For mating to flanged impulse lines

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

Feature	Benefit
Two Block Valves + Equalizer	Complete control of transmitter
Direct Mount to Transmitter	Eliminates impulse lines, reduces leak points
In-Situ Calibration	Zero and span without removal
Steam Service Compatible	Prevents thermal shock during start-up
Bleed Ports (Optional)	Vent/drain capabilities
Multiple Handle Options	Standard T-bar, wheel, or locking

Technical Specifications

Specification	Details
Material	SS316/L (standard), SS304, Carbon Steel, Duplex, Hastelloy
Pressure Rating	3000 PSI (standard), 6000 PSI, 10,000 PSI
Temperature	-65°F to 600°F (-54°C to 315°C); High-temp to 1200°F available
Process Connections	1/4″, 1/2″ NPT/Female
Transmitter Connection	1/4″ NPT (standard), 1/2″ NPT, or as required
Equalization Port	Internal within manifold body
Bleed Connections	1/4″ NPT (optional)
Mounting	Direct mount to transmitter or inline
Valve Type	Needle valves (standard), Ball valves (optional)
Stem Packing	PTFE (standard), Grafoil (high-temp), Viton (chemical)

3-Valve Manifold Types

By Mounting:

Type	Description	Best For
Direct Mount	Bolts directly to transmitter (Rosemount, Yokogawa, etc.)	Most applications, eliminates impulse lines
Inline	Mounts in impulse lines	When direct mount not possible
Flanged	Flanged process connections	High-pressure, mating to flanged systems

By Valve Arrangement:

Arrangement	Block Valves	Equalizer	Typical Use
Standard	Both blocks on same side	Center	General purpose
Opposed	Blocks on opposite sides	Center	Space constraints
Angle Pattern	Valves at 90°	Center	Tight installations

By Features:

Feature	Description	Application
With Bleeds	Vent/drain ports on each side	Liquid service, trapping concerns
With Test Ports	Connections for calibration equipment	Frequent calibration
High-Temperature	Extended stem, Grafoil packing	Steam, hot process
Oxygen Clean	Special cleaning, no lubricants	Oxygen service

Standard Bolt Patterns (Direct Mount)

Transmitter Brand	Model Series	Bolt Spacing	Manifold Pattern
Rosemount	3051, 2051	2-1/8″ (54mm)	Standard
Rosemount	1151	2-1/8″ (54mm)	Standard
Yokogawa	EJA Series	54mm	Standard (compatible)
Honeywell	ST 3000	54mm	Standard (compatible)
ABB	2600T	54mm	Standard (compatible)
Siemens	SITRANS P	54mm	Standard (compatible)
Foxboro	I/A Series	54mm	Standard (compatible)
Endress+Hauser	Cerabar, Deltabar	54mm	Standard (compatible)

Industry Applications

Industry	Typical Manifold	Special Features
Oil & Gas Production	3-valve, 6000 PSI	NACE MR0175, RTJ flange options
Refineries	3-valve, 3000 PSI	High-temp packing, fire-safe
Chemical Plants	3-valve, 3000 PSI	Hastelloy for corrosive, PTFE packing
Power Generation	3-valve, 6000 PSI	High-temp, extended stem
Steam Service	3-valve, 3000 PSI	Grafoil packing, condensate handling
Gas Processing	3-valve, 6000 PSI	NACE, low-temp options
Pharmaceutical	Sanitary diaphragm manifold	Electropolished, USP

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

Feature	Benefit
All Functions in One Body	Complete control, minimal connections
Individual Side Vents	Vent/drain each side independently
Calibration Ports	Connect calibrator without disassembly
Positive Isolation	Double block available on each side
Compact Design	All functions in one compact package

Technical Specifications

Specification	Details
Material	SS316/L (standard), SS304, Carbon Steel, Duplex, Hastelloy
Pressure Rating	3000 PSI (standard), 6000 PSI
Temperature	-65°F to 600°F (-54°C to 315°C)
Process Connections	1/2″ NPT/Female (standard)
Transmitter Connection	1/4″ or 1/2″ NPT
Vent Connections	1/4″ NPT (standard)
Mounting	Direct mount to transmitter
Valve Type	Needle valves (all)
Handle Configuration	All handles on same side for easy access

5-Valve Manifold Types

Type	Configuration	Best For
Standard	All valves accessible from front	Panel mounting, easy access
Compact	Smaller footprint	Tight spaces
With Test Ports	Additional 1/4″ ports on vents	Frequent calibration

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

Feature	Benefit
Two-Ferrule System	Independent sealing and gripping
No Tube Rotation	No scoring, ideal for thin-wall tubing
Vibration Resistant	Back ferrule absorbs movement
Reusable	Multiple assembly cycles
Wide Temperature Range	-425°F to 1200°F
Broad Pressure Range	Vacuum to 6000 PSI
Material Consistency	Same alloy throughout
Interchangeable	Industry-standard dimensions

Technical Specifications

Specification	Details
Material	SS316/L (standard), SS304, SS316Ti, SS321, Monel, Hastelloy, Inconel, Titanium
Tube Size Range	1/8″, 3/16″, 1/4″, 5/16″, 3/8″, 1/2″, 5/8″, 3/4″, 1″ OD; Metric: 3mm to 25mm
Pressure Rating	Up to 6000 PSI (depending on size and material)
Temperature Rating	-425°F to 1200°F (-254°C to 649°C)
Thread Standards	NPT (ASME B1.20.1), BSP (ISO 228), Metric
Fitting Configurations	Straight, Elbow, Tee, Bulkhead, Union, Cross, etc.
Ferrule Material	Same as body (standard); Hardened available
Surface Finish	As-machined, passivated, electropolished
Testing	100% pressure tested

Complete Tube Fitting Range

Connectors:

Type	Description	Typical Use
Straight Connector	Male/Female thread to tube	Connect tube to threaded port
Union	Tube to tube, straight	Extend tube runs
Reducing Union	Connect different tube sizes	Transition between sizes
Bulkhead Union	Through-panel connection	Panel feed-through
Swivel Connector	Rotatable thread	Orient fittings easily

Elbows & Tees:

Type	Description	Typical Use
90° Elbow	Change direction	Corners, space constraints
45° Elbow	Gentle direction change	Gradual turns
Tee	Three-way connection	Branch lines
Cross	Four-way connection	Manifold applications

Special Purpose:

Type	Description	Typical Use
Bulkhead Connector	Panel mount with thread	Through-panel connections
Port Connector	Direct to component	Valve and instrument ports
Plug	Seal unused ports	Future expansion
Cap	Seal tube end	Temporary closures
Ferrule Set	Replacement ferrules	Maintenance

Tube Fitting Configurations

Configuration	Sizes Available	Pressure Rating
Straight Thread Connector	All sizes	6000 PSI
Straight Tube Union	All sizes	6000 PSI
90° Elbow	All sizes	6000 PSI
45° Elbow	All sizes	6000 PSI
Tee (Equal)	All sizes	6000 PSI
Tee (Reducing)	Selected sizes	6000 PSI
Bulkhead Union	1/8″ to 1/2″	6000 PSI
Bulkhead Connector	1/8″ to 1/2″	6000 PSI
Swivel Elbow	1/4″ to 1/2″	3000 PSI
Swivel Tee	1/4″ to 1/2″	3000 PSI
Cross	1/4″ to 1/2″	6000 PSI
Plug	All sizes	6000 PSI
Cap	All sizes	6000 PSI

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

Specification	Details
Material	SS316/L, SS304/L
Tube End	Double compression fitting for 1/8″ to 1″ OD tube
Pipe End	Male or female NPT/BSP, 1/8″ to 1″
Pressure Rating	6000 PSI
Temperature	-425°F to 1200°F

Available Configurations

Type	Tube End	Pipe End	Application
Male Adapter	Tube fitting	Male NPT	Connect tube to female pipe port
Female Adapter	Tube fitting	Female NPT	Connect tube to male pipe thread
Bulkhead Adapter	Tube fitting	Male NPT with nut	Panel mount

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

Specification	Details
Material	SS304/L, SS316/L, SS321, SS347
Standard	ASTM A269 (welded & drawn), ASTM A213 (seamless)
Size Range	1/8″ to 1″ OD (3mm to 25mm metric)
Wall Thickness	0.028″ to 0.095″ (standard); Custom available
Temper	Annealed for bending
Lengths	20 ft (6m) random, 20 ft cut lengths
Surface	Bright annealed, pickled, or electropolished
Testing	Hydrostatic, eddy current, or pneumatic
Certification	EN 10204 3.1

Tubing Selection Guide

Tube Size OD	Wall Thickness	Working Pressure (SS316)	Bend Radius
1/4″	0.035″	3000 PSI	1″
1/4″	0.049″	5000 PSI	1-1/4″
3/8″	0.035″	2000 PSI	1-1/2″
3/8″	0.049″	3200 PSI	1-3/4″
1/2″	0.035″	1400 PSI	2″
1/2″	0.049″	2200 PSI	2-1/4″
1/2″	0.065″	3200 PSI	2-1/2″
3/4″	0.049″	1500 PSI	3-1/2″
3/4″	0.065″	2100 PSI	4″
1″	0.065″	1500 PSI	5″
1″	0.083″	2000 PSI	6″

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

Type	Description	Application
Single Test Valve	One valve with quick-connect fitting	Simple test points
Double Block & Bleed	Two isolation valves with bleed	Positive isolation for calibration
Calibration Manifold	Multiple valves in one body	Frequent calibration points
Sample Valves	Needle valve for sampling	Process sampling

Appendix: Hook-Up Components Quick Reference Table

Component	Typical Sizes	Typical Pressure	Common Materials	Applications
Root Valve (Single)	1/4″ – 1″	3000-6000 PSI	SS316, CS	General isolation
Root Valve (DBB)	1/2″	3000-6000 PSI	SS316	Critical isolation
2-Valve Manifold	1/4″ – 1/2″	3000-6000 PSI	SS316	Liquid DP
3-Valve Manifold	1/4″ – 1/2″	3000-6000 PSI	SS316	Steam, gas, general
5-Valve Manifold	1/2″	3000-6000 PSI	SS316	Critical, calibration
Condensate Pot	2″ – 6″ x 8-24″	3000 PSI	SS316, CS	Steam service
Syphon (Pigtail)	1/4″ – 1/2″	3000-6000 PSI	SS316	Steam gauge protection
Snubber	1/4″ – 1/2″	6000 PSI	SS316	Pulsation dampening
Tube Fitting	1/8″ – 1″	6000 PSI	SS316	All connections
Tubing	1/4″ – 1″	varies	SS316	Impulse lines
Test Valve	1/4″	6000 PSI	SS316	Calibration points
Bleed Valve	1/4″	6000 PSI	SS316	Vent/drain
Mounting Bracket	various	N/A	SS304	Support
Tube Clamp	1/4″ – 1″	N/A	SS304, Plastic	Tube support