Instrumentation valves provide the interface between process piping and measurement instruments, pressure transmitters, gauges, level transmitters, and flow elements. They must provide reliable isolation, calibration capability, and leak-tight sealing in a compact package.
AQ Process Systems sources and exports needle valves, manifold valves (2, 3, and 5-valve configurations), gauge root valves, block & bleed valves, and double block & bleed (DBB) valves. Standard material is SS 316 with a variety of end connections, 1/2" NPT, 1/4" NPT, tube fittings, and flanged.
All instrumentation valves are tested to API 598 or equivalent standards and marked per MSS SP-25. Fugitive emission testing to ISO 15848 is available for environmentally sensitive applications.
| Product | Specification | Description |
|---|---|---|
| Needle Valves | ||
| Standard Needle Valves | 1/4", 1" | 6000 PSI | SS 316 | NPT or tube | Precision needle valves for instrument isolation, gauge root, and sampling, bar stock SS 316 construction. |
| Integral Bonnet Needle Valves | 1/4", 1/2" | 10,000 PSI | Zero leak | High-pressure integral bonnet needle valves with metal-to-metal backseat, for HP service and zero-leakage requirements. |
| Manifold Valves | ||
| 2-Valve Manifolds | Block + bleed | For gauge and DP transmitters | Two-valve manifolds providing isolation and bleed for pressure gauges and gauge pressure transmitters. |
| 3-Valve Manifolds | Block + equalise + block | For DP transmitters | Three-valve manifolds for differential pressure transmitters, two block valves and one equalising valve for safe calibration. |
| 5-Valve Manifolds | Block + drain + equalise | For DP transmitters | Five-valve manifolds adding two drain/vent valves to the 3-valve configuration, for complete transmitter isolation, venting, and calibration. |
| Block & Bleed | ||
| Block & Bleed Valves | Single block + bleed | Compact integral body | Compact block and bleed valves providing isolation and pressure relief in a single body, for instrument connections and sampling. |
| Double Block & Bleed Valves (Instrument) | Twin needle + bleed | Positive isolation | Double block and bleed instrument valves providing two independent seals with a bleed between, for positive isolation verification. |
| Gauge Root Valves | 1/2" | Integral flange or threaded | Gauge root (gauge snubber) valves combining isolation and dampening for direct-mount pressure gauge connections. |
A 3-valve manifold has two block valves (HP and LP side) and one equalising valve, used with differential pressure (DP) transmitters. During normal operation, both blocks are open and the equaliser is closed. For calibration, the blocks are closed and the equaliser opened to zero the transmitter. This allows safe in-service calibration without removing the transmitter from the process.
SS 316 is the standard material for most instrumentation valves, it provides corrosion resistance, compatibility with most process fluids, and adequate strength for high pressures. For more aggressive fluids, Monel, Inconel, Hastelloy, or duplex SS are available. Carbon steel is used for clean, non-corrosive service where cost is a priority.
Yes. Instrumentation needle valves are available with 1/4" and 1/2" compression tube fitting ends (compatible with Swagelok, Parker, Ham-Let), as well as NPT, BSP, socket-weld, and flanged end connections. We match the end connection to your existing tubing system.
Block & bleed has one isolation valve and one bleed/vent valve, suitable for general instrument isolation. Double block & bleed (DBB) has two independent isolation valves with a bleed between them, allowing positive isolation verification (open the bleed to confirm both blocks are sealing). DBB is required for critical and safety-related instrument isolations.
Yes. We supply manifold valves configured for direct-mount and remote-seal DP transmitter installations, including flange-mounted manifolds (direct to the transmitter), pipe-mounted manifolds, and compact configurations for close-coupled installations.
Share your valve specification, size, pressure class, material, end connections, we respond within 24 hours.