Pressure Gauge Attributes: Specs, Standards & Data Fields

Core

Every SKU needs these. Without them the record is not a product, it is a row.

AttributeExampleWhy it matters

Gauge Type

enum

Bourdon tube, C-type

Bourdon tube, diaphragm and capsule elements suit different pressure bands and media. The element type gates every downstream spec.

Nominal Dial Size

enum · in [NS mm]

4 in [NS 100]

Panel cutouts and readability are fixed by dial size. ASME sizes the dial in inches; EN 837-1 sizes the case in millimetres.

Pressure Range (Scale Range)

range · psi

0 to 160 psi

The primary filter. Buyers size so normal operating pressure sits in the middle third of the scale.

Scale Unit

enum

psi / bar dual scale

Plants standardise on psi, bar, kPa or kg/cm². Dual-scale dials are a separate SKU, and the wrong unit is an unusable gauge.

Process Connection Size & Thread Standard

enum

1/4 in NPT male (ANSI/B1.20.1)

NPT, G and R are not interchangeable. '1/4' on its own does not tell a buyer whether the thread will seal.

Connection Location

enum

Lower mount (radial)

Decides whether the gauge mounts on a line stub or through a panel. Lower, lower-back and centre-back are different parts.

Accuracy Grade / Class

enum

Grade 1A, ±1% of span (EN 837-1 Class 1.0)

What test, process and general-service buyers compare on. Grade also sets the minimum usable dial size.

Wetted Parts Material

enum

Stainless steel 316L (1.4404)

Media compatibility is decided by the socket and Bourdon tube, not the case. The most common root cause of gauge failure.

Case Filling

enum

Glycerine

Glycerine or silicone damps pointer flutter on pumps and compressors, but narrows the permissible medium temperature range.

Manufacturer Part Number

identifier

233.50.100

The MRO counter reorders by MPN. Cross-reference, supersession and warranty all hang off it.

Differentiating

What buyers actually compare on. This is where catalogs win or lose the filter.

AttributeExampleWhy it matters

Case Material

enum

Stainless steel 304 (1.4301)

Drives corrosion resistance of the enclosure and price. Stainless, brass/aluminium and painted steel sit at different points.

Overpressure / Pressure Limitation

text

Steady 1.0 × FS; fluctuating 0.9 × FS; short-time 1.3 × FS

Steady, fluctuating and short-time limits are multiples of full scale and differ by nominal size. Decides survival on pump discharge.

Medium Temperature Range

range · °C

-20 to +100 °C (glycerine filled)

Filling narrows it sharply: unfilled reaches +200 °C, glycerine stops at +100 °C. Steam and hot oil lines fail on exactly this.

Ingress Protection Rating

enum

IP65 per IEC/EN 60529

Washdown and outdoor installs specify IP65 or IP66 per IEC/EN 60529. A filter buyers reach for and catalogs often leave blank.

Compliance & identifiers

Standards, regulatory data, and the identifiers channels reject you for missing.

AttributeExampleWhy it matters

Safety Pattern (EN 837-1)

enum

S3 (solid front, blow-out back)

S3 requires a solid baffle wall, blow-out back and non-splintering window. Gas and refinery specs mandate it by name.

Hazardous Area Approval

enum

ATEX II 2G Ex h IIC T6...T1 Gb X

Zone 1 and Zone 21 installations need the ATEX marking carried on the record, not buried in the operating manual.

GTIN / UPC

identifier

00846845012347

Required to list on Amazon Business and to exchange product data under the ASA Product Data Standard.

Country of Origin

enum

Germany

Drives tariff classification, Buy American / TAA eligibility on federal and utility work, and marketplace listing.

The fields that aren't in the schema at all

What most pressure gauges catalogs are missing.

The table above is the schema most catalogs already have. These are the attributes that usually aren't in it — each one surfaced by a signal from the live market rather than by an audit of what's already there. This is what Anglera's Schema Foundry does on a real catalog, in this category.

Supplier signal

+ Safety Pattern (EN 837-1 S1 / S2 / S3)

Manufacturer datasheets state safety level in one line — 'Safety level S1 per EN 837-1' — and sell solid-front S3 as separate models. Distributor catalogs rarely carry a safety pattern field at all.

Solid-front S3 gauges cannot be filtered or specified. Gas-service and refinery RFQs that mandate solid front plus blow-out back go to whoever can show it.

Search signal

+ Canadian Registration Number (CRN)

Datasheets list CRN as an approval for full scale values up to 1,000 bar, and buyers shipping skids into Canadian provinces search for it by name. Most US distributor catalogs expose no CRN field.

Canadian work needs provincial registration for pressure-retaining instruments. Without the field, quotes stall or the gauge is rejected at site inspection.

Search signal

+ Oxygen Service Cleaning (oil- and grease-free)

Manufacturers offer an 'oil- and grease-free for oxygen' version and mark the dial USE NO OIL. Buyers search for oxygen service gauges and get the standard glycerine-filled SKU back.

A glycerine-filled or uncleaned gauge in oxygen service is a hydrocarbon ignition source. Wrong-part shipment with genuine safety exposure, plus the return.

Supplier signal

+ Overpressure / Pressure Limitation

Datasheets give steady, fluctuating and short-time limits as multiples of full scale, and sell increased overload safety at 2× to 5×. Catalogs typically publish only the scale range.

Buyers size on scale range alone, over-range the gauge on pump discharge, and return bent-pointer units as defective warranty claims.

Supplier signal

+ Restrictor / Snubber Orifice

Datasheets list screwed-in restrictors at Ø0.6 mm and Ø0.3 mm as an order option; pulsation is a common failure mode on positive-displacement pump discharge. Almost no catalog carries the field.

Pulsation-damaged gauges come back as warranty. The upsell to a restrictor-fitted or filled gauge is invisible at the point of sale.

How Schema Foundry finds these

Messy in, governed out.

The same value, spelled every way pump, valve & process equipment suppliers spell it. A filter only works once they agree.

Process Connection Size & Thread Standard

1/4 NPT1/4" MNPT¼ NPT MNPT 1/4 maleG1/4BR1/4

1/4 in NPT male (ANSI/B1.20.1)

G¼ (EN 837-1) and R¼ (ISO 7) are not NPT. Collapsing them all to '1/4' ships a thread that will not seal.

Nominal Dial Size

4"100mmNS1004 inØ1004-1/2"

4 in [NS 100]

4 in and NS 100 cross-reference; 4½ in (114 mm) is a distinct US size with no metric twin. Merging them mis-sizes panel cutouts.

Case Filling

Glycerine FilledGly. FilledLiquid-filledGlycerinGFFilled

Glycerine

'Liquid-filled' hides whether the fill is glycerine, glycerine-water or silicone oil — which is what sets the medium temperature range.

Accuracy Grade / Class

1%±1% FSGrade 1AClass 1.01% of spanASME 1A

Grade 1A, ±1% of span

ASME B40.100 grades and EN 837-1 classes appear on one datasheet. '1%' alone never says whether it is full span or three-zone.

What buyers ask

Every one of these should be answerable from the attributes above. If it isn't, that's a gap.

Will this handle my media, or do I need 316L wetted parts?
Is 4 inch the same as NS 100? My drawing calls out 100 mm.
Is this 1/4 NPT or G1/4? The supplier sheet just says 1/4.
Do I need a liquid fill, or will a dry gauge survive pump discharge?
What happens if the line spikes past full scale on a 160 psi gauge?
Does this gauge have a CRN? The skid ships to Alberta.
Can I use this on oxygen service?
Does it carry an ATEX marking for our Zone 1 area?

What channels require

The same SKU, different mandatory fields per destination.

Distributor's own faceted site

Nominal Dial SizePressure RangeProcess Connection Size & ThreadAccuracy GradeCase FillingWetted Parts Material

Amazon Business

GTIN / UPCBrandManufacturer Part NumberCountry of OriginPackage DimensionsProduct Images

ASA Product Data Standard (PHCP/PVF)

UPCManufacturer Part NumberBrandProduct DescriptionDimensionsMaterial

OEM / EPC spec submittal packages

Wetted Parts MaterialAccuracy GradeSafety Pattern (EN 837-1)Hazardous Area ApprovalEN 10204 3.1 certificateCRN

Pressure Gauges data, in practice

Is a 4 in dial the same as NS 100?

They cross-reference, but they are not the same measurement. ASME B40.100 sizes a gauge by the diameter of the dial in inches; EN 837-1 sizes it by the diameter of the case in millimetres. A manufacturer will list NS 63 [2½"], NS 100 [4"] and NS 160 [6"] as one line each, so 4 in and NS 100 are safely the same SKU. The trap is 4½ in: a distinct US size of roughly 114 mm with no metric equivalent, carrying meaningfully more dial surface than a 100 mm case. If your schema stores dial size as loose text, 4", 4-1/2", 100mm and NS100 land in one bucket and mis-size panel cutouts. Store it as a governed enum carrying both the inch and NS value.

How do ASME accuracy grades map to EN 837-1 classes?

They do not map cleanly, and both appear on the same datasheet. ASME B40.100 grades 1A through 4A state accuracy as ±% of span across the entire span: 1A is ±1%, 2A ±0.5%, 3A ±0.25%, 4A ±0.1%. Each grade also carries a minimum recommended dial size — 4A wants 8½ in, 3A wants 4½ in, 2A wants 2½ in. Separately, grades A through D state accuracy in three zones — lower ¼, middle ½, upper ¼ — so Grade A reads ±2% | ±1% | ±2% of span. EN 837-1 instead uses classes as ±% of span, such as 1.0 and 1.6. A single model line will be EN Class 1.6 / ASME Grade A at NS 63 and EN Class 1.0 / ASME Grade 1A at NS 100 and NS 160. Carry both values.

Why does wetted parts material need its own field, separate from case material?

Because the case and the wetted path are frequently different metals, and only the wetted path decides media compatibility. A stainless case with a brass socket and bronze Bourdon tube is a common and much cheaper build than an all-316L gauge, and the two look identical on a shelf. What the media touches is the process connection and the measuring element — commonly 316L (1.4404), but also Monel 400, Hastelloy C-276 or tantalum on aggressive service. Sour service adds NACE MR0175 / ISO 15156 in H2S environments. Diaphragm-seal versions move the wetted material to the seal entirely. If the record says only 'stainless steel', a buyer cannot tell which part is stainless.

What is the difference between full scale and overpressure limit?

Full scale is the top of the printed dial. The pressure limitation is what the gauge survives, and it is stated as multiples of full scale, split three ways. For NS 100 and NS 160 a typical Bourdon gauge takes steady pressure at full scale, fluctuating at 0.9 × full scale, and short-time at 1.3 × full scale. NS 63 is more restrictive: steady at ¾ full scale, fluctuating at ⅔, short-time at full scale. Manufacturers also sell increased overload safety at 2×, 3×, 4× or 5× as an order option, and vacuum resistance to -1 bar as another. The practical selection rule is to put normal operating pressure in the middle third of the scale, which leaves headroom for spikes.

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