5 Way Manifold Valve Manufacturer — Coplanar, Direct-Mount DP Transmitter Manifolds

A 5-way (5-valve) manifold valve is a compact instrument manifold that integrates five valves in a single forged block: two block/isolation valves, one equalizing valve and two vent/calibration valves. It isolates a differential-pressure (DP) transmitter from the process, equalizes the high and low sides for zero-setting, and lets the transmitter be vented, drained or calibrated in place. It replaces several separate valves and fittings, cutting leak paths, weight and installation time.

A coplanar manifold bolts directly onto the coplanar process flange at the base of a DP transmitter, so there is no impulse tubing between the manifold and the instrument. The two block valves connect the high- and low-pressure impulse lines to the cell, the equalizing valve links both sides, and the vent/calibration valves allow venting and test connections. Direct mounting follows IEC 61518 spacing and gives a close-coupled, leak-tight, low-weight assembly.

A 3-way manifold has three valves — two block valves and one equalizing valve — enough to isolate a DP transmitter and equalize it for zero-setting. A 5-way manifold adds two vent/calibration valves, so the transmitter can be vented, drained and calibrated in place without disturbing the impulse lines or removing the instrument. Choose a 3-way for basic isolation and a 5-way when on-line calibration and venting are required.

Integrating five functions in one forged block removes multiple threaded joints, tube fittings and pipe nipples, which are the usual leak and emission points in an impulse system. It saves weight and panel space, speeds installation, and gives a repeatable, factory-tested assembly. For DP measurement it also enforces the correct isolate-equalize-vent sequence, protecting the transmitter cell from one-sided overpressure during start-up and shutdown.

On a typical 5-valve manifold, the high-pressure and low-pressure block valves isolate the transmitter from the two impulse lines; the equalizing valve connects the high and low sides to give zero differential for zero-checking and to protect the cell; and the two vent/calibration valves let each side be vented, drained or connected to a calibration reference or test gauge. Exact configurations can vary by design.

To put a DP transmitter into service, start with both block valves closed and the equalizing valve open. Open the high-pressure block valve slowly to pressurise both sides of the cell, then close the equalizing valve, then open the low-pressure block valve — the transmitter now reads true differential pressure. To remove it, open the equalizing valve first, then close the low- and high-pressure block valves and vent. This protects the cell from one-sided overpressure.

Stainless-steel 5-way manifolds are commonly rated up to 6000 psi (about 413 bar) at ambient temperature, with brass versions in lower 300, 1000 and 3000 psi classes. The allowable working pressure derates as temperature rises and depends on body material, seat and packing. Exact ratings are confirmed against the body material and service conditions on each order, and higher classes are available depending on design and application.

Temperature capability is set mainly by the packing and seat. Standard PTFE packing suits roughly −40°C to +232°C (450°F); graphite/Grafoil packing extends service to higher temperatures for steam and hot hydrocarbon duties. Soft (PTFE) seats give bubble-tight shut-off at moderate temperatures, while metal seats suit higher temperatures. The correct packing and seat are selected for your process temperature.

SS316/316L is the default because its molybdenum content gives strong resistance to chloride pitting, offshore and marine atmospheres, and a wide range of process media, while keeping good strength and weldability. It carries EN 10204 3.1 traceability and can be supplied to NACE MR0175 for sour service. For more aggressive media, higher alloys such as Monel, Inconel, Hastelloy, duplex or Alloy 20 are used.

Bodies and trim are available in SS316/316L (standard) and SS304, plus Monel 400, Inconel 625/825, Hastelloy C276, duplex 2205 and super duplex 2507, Alloy 20, titanium, carbon steel (A105) and brass. Material is selected for the corrosivity, pressure, temperature and any sour-service (NACE MR0175/ISO 15156) requirement, and supplied with 3.1 material test certificates and PMI on request.

Process and instrument connections are available as NPT, BSPT (R) and BSPP (G) threads — male or female — and as socket-weld, butt-weld or flanged ends, plus twin-ferrule compression tube fittings in 1/4″, 3/8″ and 1/2″ OD and 6, 8, 10 and 12 mm OD tube. The transmitter side mounts to the coplanar/flanged interface per IEC 61518. Connection type and size are made to your impulse-line and transmitter requirements.

Relevant standards include IEC 61518 for the mating dimensions between DP/pressure transmitters and manifolds, ASME B1.20.1 for NPT threads, ISO 7-1/ISO 228 for BSP threads, ASTM A182/A479 for stainless forgings and bar, NACE MR0175/ISO 15156 for sour service, MSS SP-99 for instrument valves, and API 598 / BS EN 12266 for pressure testing. CE/PED 2014/68/EU compliance is available for European export.

Yes. For wet H₂S (sour) service the manifold is supplied to NACE MR0175 / ISO 15156, using qualified materials and controlled hardness (typically not exceeding 22 HRC for 316), with hardness testing and 3.1 certification. This is standard for upstream oil and gas, offshore and refinery DP measurement where hydrogen sulphide is present.

Every manifold is hydrostatically shell-tested for body strength and seat-leak tested for tightness, typically to API 598 / BS EN 12266. Inspection also covers positive material identification (PMI), dimensional and thread/port gauging, hardness (including NACE), surface finish and functional operation of each valve. Material traceability is by EN 10204 3.1 certificates and heat-number marking, and third-party inspection (LR, BV, DNV, SGS, TÜV, IBR) is welcomed.

Yes. Coplanar 5-way manifolds are designed to bolt directly to coplanar-style DP transmitters — for example the Rosemount 3051C and equivalent coplanar instruments — using the IEC 61518 bolt pattern and process spacing. This eliminates the impulse tubing between manifold and transmitter and creates a compact, close-coupled assembly. Confirm the transmitter make, model and flange pattern when ordering.

A coplanar (direct-mount) manifold bolts straight onto the transmitter flange, removing the tubing between manifold and instrument, cutting leak points and weight and speeding installation. A conventional remote (inline/pipe-mounted) manifold sits away from the transmitter and is joined by impulse tubing, which adds joints, weight and measurement lag. Direct-mount coplanar is preferred where space, weight and reliability matter; remote mounting suits high-temperature or vibration isolation needs.

Twin-ferrule compression tube fittings give a gas-tight, vibration-resistant, easily re-made connection that suits instrument impulse tubing, while tapered NPT/BSP threads with sealant are common for process connections. Tube fittings reduce the risk of leaks under vibration and thermal cycling; threaded ends are simple and widely standardised. Many manifolds combine a threaded process side with tube-fitting instrument connections.

5-way coplanar manifolds are used wherever differential pressure is measured for flow, level or filtration: oil and gas (upstream, refining, pipelines), petrochemical and chemical plants, power generation, marine and offshore platforms, hydrogen and LNG, water and wastewater treatment, and instrumentation panels and process-automation skids. They suit any DP transmitter installation needing isolation, equalizing and in-place calibration.

Yes. Manifolds are made to order — body material, port arrangement, mounting pattern, thread and tube sizes, seat and packing, NACE compliance, oxygen-service cleaning, special tagging and certification are all configurable. We also manufacture to customer drawings and offer private-label / OEM supply for valve brands and instrument packagers, with consistent quality and traceability.

To quote we need the manifold type (3/5-valve) and mounting (coplanar or remote), the transmitter make/model and flange pattern, body material and any NACE requirement, the process and instrument connection types and sizes, the service pressure and temperature, packing/seat preference, quantity, tagging and certification (3.1, NACE, PED) and any third-party inspection. Tesco Steel & Engineering is ISO 9001:2015 certified and exports worldwide.