NMX‑PRP‑200 / Rev 01 / NAB · 70/30 CuNi · NES 314 / Noida · India 2026 · Product Page

NMX-PRP-200 · UNDER CONTRACT

Naval pressure reducing panels. 200 bar in, constancy out.

Group-mounted reducing stations for warship high-pressure air: a dome-loaded reducing valve, relief protection, and glycerine-filled gauges on one SS 316 panel between a single inlet and outlet — stepping 200 bar down through eight duty ratings to outlets from 4 to 150 bar, and holding outlet pressure and flow constant while the air bottles fall from 200 to 120 bar. Nickel-aluminium-bronze and 70/30 copper-nickel throughout, under contract for multiple ship sets of an Indian warship-building programme.

Enquire — reducing panels Capability sheet (PDF)

Naval pressure reducing panel — dome-loaded pressure reducing valve with bolted dome cap, relief valve, Y-strainer, gauges and stop valves on a stainless steel plate against a warship bulkhead

Fig · 01 The group reducing station — representative configuration of the contracted panel type

HP Air Inlet

200bar · design 0–200

Duty Ratings

8outlets · 4–150 bar

Panel Envelope

450× 400 mm max

Hydro & Seat Test

300bar · every panel

Metallurgy

NAB· 70/30 CuNi

ISO 9001 / 14001 Under contract — Indian warship programme Class-witnessed FATs Shock Grade “A” · MIL-STD-167 Noida · India

Overview

Stored at 200 bar. Used at almost anything else.

A warship stores its compressed air at 200 bar — but the systems that drink it want 150, 100, 50, 45, 30, 8, 7, even 4 bar. Between the bottle banks and every one of those users stands a pressure reducing panel.

Close-up of a dome-loaded pressure reducing regulator — bolted dome cap, dome gauge and small-bore loading line — with silver-brazed copper-nickel pipework on a naval panel

Fig · 02 The dome-loaded reducing valve — the gas cushion in the dome holds the outlet steady

Each PRP groups one duty onto one panel: a dome-loaded pressure reducing valve with its dome gauge and built-in relief, non-return balance stop valves at inlet and outlet, a 20-micron strainer, a bypass throttle valve, a downstream relief valve, and three glycerine-filled gauges — plumbed in 70/30 copper-nickel on an SS 316 plate no larger than 450 × 400 mm.

The dome does the regulating. A cushion of gas above the diaphragm, set through the dome regulating valve, balances the outlet against spring drift — so outlet pressure and rated flow stay constant even as the HP bottles decay from 200 to 120 bar. Twenty-nine such panels across eight duty ratings serve one ship set, from the 150-bar heavy users down to a 7-to-4 bar trim.

One inlet, one outlet, one duty — and the outlet never wanders.

Under Contract · Naval

An Indian warship-building programme

Multiple ship sets — 29 panels per set across eight duty ratings — under contract with an Indian warship-building yard, with staged deliveries against the build programme.

Inspected · Class

Witnessed at every gate

Every panel passes hydrostatic, relief-lift, seal-tightness, and accuracy-of-regulation acceptance tests — witnessed by a classification society and the shipbuilder’s inspection organisation.

Engineered · NES

Designed to the naval canon

Designed to NES 314 and NES 375, type-tested to ASTM F 1685, with ANSI B16.34 valves and ASME B31.3 pipework practice — the standards frontline navies build to.

Construction

Bronze, cupronickel, and no shortcuts.

A reducing panel earns its place on a warship through metallurgy and pipework discipline. The schematic below is the whole valve train — every element the specification demands, in the order the air meets it.

FIG · 03PANEL SCHEMATIC · VALVE TRAIN · REGULATION

Fig · 03 Group reducing station — balance stop valves, 20 µ strainer, dome-loaded reducing valve, relief, bypass throttle

Con · 01

The Valve Train

Non-return balance stop valves at inlet and outlet, 20-micron sintered-bronze strainer, dome-loaded reducing valve with dome gauge and built-in relief, dome regulating valve, downstream relief valve, bypass throttle valve, three glycerine-filled gauges with stop-and-release valves, and a depressurisation provision for safe maintenance.

Con · 02

Naval Metallurgy

NAB valve bodies (NES 833), 70/30 copper-nickel pipe (NES 780), phosphor-bronze internals (NES 838), Monel K400 springs, nitrile elastomers (NES 337), SS 316 handwheels, gauges and panel plate — and forged NAB fasteners (NES 862) with rolled threads and virgin-material certification.

Con · 03

Pipework Discipline

No bends by bending — direction changes use fittings, silver-brazed to BS 1845 Ag14. BSP parallel threads to BS 21G, anti-blow-out valve stems, flow areas at least 90% of full bore, and velocities held to 8–10 m/s.

Con · 04

Built for the Ship

Shock grade “A”, vibration to MIL-STD-167 Type I, airborne noise to MIL-STD-740-2 — qualified for roll of ±30°, pitch of ±10°, 20° list, 5° trim, and sea state 7 survival, on a panel of 450 × 400 mm or less.

Holding a pressure-reducing-panel or naval valve tender? Send it across — clause-by-clause compliance matrix within two working days · [email protected]

Send tender spec

Specifications

Reference specification, as contracted.

The parameters below reflect the panels under contract for an Indian warship programme. Duty ratings, connections, and documentation are re-scoped against your specification.

Full specification — expand

Product	Naval pressure reducing panel (PRP) · group reducing station for HP air · single inlet / single outlet
Duty Ratings (8)	200→150 · 200→100 · 200→50 · 200→45 · 200→30 · 200→8 · 200→7 · 7→4 bar — one duty per panel · 29 panels per ship set
Regulation	Outlet pressure and rated flow held constant as inlet decays from 200 to 120 bar · repeatability proven over 25 consecutive test cycles
Flow Capacity	Duty-specific — up to 360 Nm³/h on high-flow ratings
Valve Train	2 × non-return balance stop valves · 20 µ sintered-bronze strainer · dome-loaded reducing valve with dome gauge & built-in relief · dome regulating valve · pressure relief valve · bypass throttle valve · 3 × glycerine-filled gauges with stop-and-release valves · depressurisation provision · 2 × loose isolation valves per panel
Envelope & Mounting	≤450 × 400 mm · panel-mounted on SS 316 plate and brackets
Connections	Inlet 12 mm OD · outlets up to 38 mm OD · BSP parallel threads to BS 21G · 70/30 CuNi interconnecting pipe with fittings in place of bends
Design Codes	NES 314 · NES 375 · ASTM F 1685 · ANSI B16.34 · ASME B31.3 · design temperature 120 °C · velocity ≤8–10 m/s · flow area ≥90% of full bore
Materials	NAB bodies (NES 833 Pt II) · 70/30 CuNi pipe (NES 780 Pt II) · phosphor bronze (NES 838) · Monel K400 springs · nitrile seats, O-rings & diaphragms (NES 337) · SS 316 handwheels & gauges · forged NAB fasteners (NES 862), rolled threads · anti-blow-out stems · silver brazing BS 1845 Ag14
Testing — Every Panel	Hydrostatic 300 bar, 20–30 min · seat tightness 300 bar / 20 min, no leakage · bubble-tight to ANSI Class VI · FAT: visual, hydro, relief lift, seal tightness, accuracy of regulation, dynamic outlet pressure — witnessed by classification society & shipbuilder
Type Tests	ASTM F 1685 regime — pressure reversal, accuracy of regulation, pressurisation rate, shock, noise & vibration · 10,000-cycle endurance followed by hydrotest · fittings: proof 300 bar / 10 min, burst, vacuum 710 mmHg / 15 min (≤0.5% drop), impulse, 10 × dismantle–reassemble
Shipboard Environment	Shock grade “A” · vibration MIL-STD-167 Type I · airborne noise MIL-STD-740-2 · roll ±30° / 10 s · pitch ±10° / 20 s · list 20° · trim 5° · sea state 7 survival
Support	48-month warranty · 30-year product support with 2-year obsolescence notice · ILMS-coded on-board, base & depot spares · 24-month tropical preservation · SS 316 tally plates · documentation in SI units with CAD drawings
Status	Under contract — multiple ship sets for an Indian warship-building programme · staged deliveries · configurable to customer specification

PDF · 1 page

Pressure Reducing Panels — Capability Sheet

Tender Response

Send your specification — clause-by-clause compliance matrix

Variants

Eight duties, one panel discipline.

Tenders call these pressure reducing panels, PRPs, group reducing stations, or air reducing stations. The contracted family spans eight duties on a common architecture — and the architecture stretches further than the contract.

Var · 01

The Contracted Eight

From 200→150 bar mains duty down to a 7→4 bar trim — one duty per panel, 29 panels per ship set, on a common envelope, valve train, and metallurgy.

Var · 02

High-Flow Ratings

Duties rated to 360 Nm³/h with outlet connections up to 38 mm OD — the same regulation discipline at distribution-main flows.

Var · 03

Other Media & Duties

Nitrogen and other gas services, alternative inlet–outlet pairings, and shore-side letdown duties — engineered clause-by-clause against your specification.

Var · 04

Scope Beyond the Panel

Loose isolation valves, ILMS-coded spares packages, onboard installation, setting-to-work, trials support, and operator & maintainer training — contracted alongside the hardware.

Applications

Where it serves.

Wherever gas is stored high and used low — at sea and ashore.

A · 01Frontline warships — stepping 200 bar HP air down to every user system on board

A · 02Engine and generator starting-air trains — high-flow reduction that holds under demand

A · 03Control and instrumentation air — low-pressure users fed cleanly from HP mains

A · 04Naval refit yards — replacement group reducing stations for in-service ships

A · 05Shore establishments and test houses — HP air and gas letdown to bench pressures

A · 06Industrial high-pressure gas networks — 200-bar storage stepped to process pressure

FAQ

Common questions.

Plain-language answers from the engineering team.

Q · 01 What exactly is a pressure reducing panel?

A group reducing station: the reducing valve, its relief protection, its gauges, strainer, and bypass, pre-assembled and pre-piped on a single plate with one inlet and one outlet, each guarded by a stop valve. The shipbuilder makes two pipe connections and bolts up one panel — instead of assembling a dozen loose valves in a cramped compartment. Everything is set, tested, and certified before it reaches the ship.

Q · 02 How does it hold outlet pressure as the air bottles run down?

The dome. Instead of a spring alone, a sealed cushion of gas above the diaphragm — charged through the dome regulating valve and read on the dome gauge — loads the valve. Gas pressure does not drift the way spring force does across a stroke, so the outlet stays at its set value and rated flow even as the inlet decays from 200 down to 120 bar. The contracted panels prove that constancy over 25 consecutive acceptance-test cycles.

Q · 03 Why NAB and copper-nickel rather than stainless steel?

Because a warship is a salt-laden environment where brine mist reaches every compartment. Nickel-aluminium-bronze and 70/30 copper-nickel resist seawater attack and selective-phase corrosion, tolerate shock without brittle failure, and sit galvanically close to the ship’s other seawater-system metals — which is why naval engineering standards specify them for HP air fittings. Springs are Monel K400, elastomers nitrile, and everything the operator touches is SS 316.

Q · 04 What testing does each panel go through?

Every panel: 300 bar hydrostatic hold, 300 bar seat-tightness with zero permitted leakage, bubble-tight shutoff to ANSI Class VI, then a witnessed factory acceptance test covering relief lift, seal tightness, accuracy of regulation, and dynamic outlet pressure. The design itself is type-tested to the ASTM F 1685 regime — pressure reversal, pressurisation rate, 10,000 operating cycles followed by a fresh hydrotest, plus shock, noise, and vibration qualification.

Q · 05 What does shock grade “A” mean in practice?

It is the qualification for equipment that must keep working through underwater-explosion shock — the most demanding naval shock class, verified by test, not analysis alone. Add vibration endurance to MIL-STD-167 Type I, airborne-noise limits to MIL-STD-740-2, full function through roll of ±30°, pitch of ±10°, 20° of list and 5° of trim, and survival through sea state 7 — the panel is qualified for the ship’s worst day, not its average one.

Q · 06 Can you build to our tender specification exactly?

That is the standard engagement — the contracted panels were bid clause-by-clause against a warship-builder’s technical specification and are being built to it, with class-witnessed acceptance at every gate. Send yours — duties, flows, connections, standards, documentation regime — and we return a compliance matrix within two working days; export enquiries are handled the same way with formalities managed as part of the programme.

↗

High-pressure gas & naval systems from Neometrix.

Compression, storage, letdown, and dockside utilities engineered and manufactured at our Noida facility.

↗ HP Gas

Nitrogen Gas Boosting Station

High-pressure nitrogen boosting for charging and testing duties.

↗ Naval Dockside

Mobile Rectifier / Battery Charging Unit

Megawatt-class dockside DC power — delivered to Indian naval dockyards.

↗ Gaseous N2

Aircraft Tyre Nitrogen Charging Rig

Digital set-point nitrogen inflation — delivered to a DRDO establishment.

Explore our gas & cryogenics capability, or browse all Neometrix product lines.

Get a quotation

Send your pressure-reducing-panel
tender specification.

The Defence Programmes desk replies within two working days with a clause-by-clause compliance matrix and a budgetary quotation. Write to [email protected] or use the form.

Enquire — reducing panels Capability sheet (PDF) +91 7777 876 876

ISO 9001 / 14001 UNDER CONTRACT — INDIAN WARSHIP PROGRAMME CLASS-WITNESSED FATs MADE IN NOIDA · INDIA