Mounting Field Instruments in Process Plants

DECISION FRAMEWORK

Instrument stand, ModRack, or FixedRack — how to choose.

The mounting decision depends on three factors: the number of instruments being mounted in one area, the permanence of the installation, and the level of customization required.

Single instrument — Instrument Stand

When one instrument needs to be mounted at a specific point — a pressure transmitter at a vessel nozzle, a temperature element at a pipe tap, a flow meter at a process connection — the instrument stand is the correct solution. TechLine manufactures instrument stands in every standard configuration:

• Pipe mount stands: Mount to 2" process pipe using U-bolt or pipe clamp. The most common configuration for transmitters mounted directly at the process connection.
• Floor mount stands: Bolt to concrete grade or structural steel deck. For instruments that are not pipe-mounted and need a freestanding support.
• Wall mount stands: Attach to structural steel, vessel walls, or concrete. For instruments in areas where floor mounting is impractical.
• Beam mount stands: Clamp to structural steel beams. For overhead or elevated instrument locations.
• Grating mount stands: Attach through open bar grating decks. Common in refinery and chemical plant elevated deck installations.
• Cable mount stands: Mount to cable tray structure. For instruments that are located adjacent to cable tray runs.
• U-bolt mount stands: For mounting to pipe rack structure or process piping of various diameters.
• Tech-Mount Modular: TechLine's modular stand system for custom configurations that don't fit standard options.
• Capillary spool and mounting flag: For remote seal transmitters where the capillary tube requires a controlled routing path from the process connection to the transmitter.

Material options: hot-dipped galvanized (standard), aluminum, 304 stainless steel, 316 stainless steel. Stock items in standard heights and configurations ship within 24 hours. Custom configurations available.

Multiple instruments in one area — ModRack

When three or more instruments need to be mounted in the same area — an analyzer shelter, an instrument air manifold station, a group of transmitters on a common process header — ModRack provides a configurable, off-the-shelf solution that consolidates multiple instruments onto a single support structure.

ModRack uses two 84" stanchions as the base unit, with adjustable receivers that accommodate single strut, double strut, and 2" square tubing crossbars. The number of receivers — and therefore the number of crossbar positions — is specified at order time. Roof options (no roof, double roof, single-sided roof) protect mounted equipment from weather.

Why ModRack instead of individual stands: Consolidating multiple instruments onto a ModRack reduces the number of individual stand foundations, simplifies the layout of the instrument area, and creates a maintainable structure where all instruments in the group are accessible from the same location. For project work, ModRack ships as standard off-the-shelf components that are assembled in the field without cranes or heavy equipment — significant on projects where crane time is a schedule constraint.

ModRack is suitable for permanent and temporary applications. The modular components can be disassembled and reconfigured if the instrument layout changes.

Part number structure: TLMMR - [Receiver Type] - [Number of Receiver Sets] - [Material Finish] - [Cross Support Width] - [Roof Type]

Example: TLMMR-S-4-GV-0-NR = Medium duty ModRack, single strut receivers, 4 crossbar positions, galvanized, no cross supports, no roof.

Available materials: Galvanized (GV), Aluminum (AL), 304 Stainless Steel (4SS), 316 Stainless Steel (6SS). Direct burial option available — add D.B. and required length to end of part number.

Large permanent installation — FixedRack

When the installation requires a fully-welded, custom-engineered structure — large analyzer packages, electrical panel installations, remote I/O cabinet groups — TechLine FixedRack provides a complete solution built to customer drawings or specifications.

FixedRack is not a standard product with a part number — it is a custom fabrication. TechLine's engineering team works from customer drawings or stated specifications to design and fabricate racks in any size, any configuration, and any material. Heavy duty and light duty options. Single or double sided. Optional roofing. Galvanized, aluminum, 304SS, 316SS, painted finishes.

FixedRack ships fully assembled and ready to install. No field fabrication of the support structure. Bolt it down and mount the equipment.

When to specify FixedRack over ModRack: The deciding factor is permanence and load. ModRack is designed for flexible, adjustable configurations in moderate load applications. FixedRack is for permanent installations where the equipment layout is known, the loads are defined, and the structure needs to meet a specific engineering specification. On large EPC projects with hundreds of identical racks, FixedRack fabrication to a standard drawing is more cost-effective than assembling hundreds of ModRack units.