Baumer supplier in India
Baumer Steel Case Low & High Pressure Gauge — AP Model, Diaphragm Type
Diaphragm-type pressure gauge for demanding low-pressure (mmWC) and high-pressure (kg/cm²) applications. Stainless steel case and measuring system, flanged or screwed connection, EN 837-3 basis, with CE & ATEX approved electrical contacts available for alarm and interlock duty.
About The Product
What Is the Baumer Steel Case Diaphragm Pressure Gauge (AP Model)?
The Baumer AP Model is a stainless steel, diaphragm-type pressure gauge built on the general requirements of EN 837-3. Unlike Bourdon tube gauges, the AP Model measures pressure through the deflection of a flexible diaphragm — a design that excels at very low pressures, gaseous media, and corrosive or viscous fluids that would be difficult for a Bourdon tube to handle cleanly.
The AP Model is available in two pressure classes: LP (Low Pressure), covering -6000 mmWC to 0 and 0 to 6000 mmWC for HVAC, clean-air and low-pressure gas duty; and HP (High Pressure), covering -1 kg/cm² to 0 and 0 to 25 kg/cm² for general process and chemical applications. Both share a stainless steel case, bezel, top chamber and movement, with the bottom chamber and diaphragm available in a wide range of corrosion-resistant materials — from AISI 316 SS through to PVDF, Hastelloy C, and Monel.
Optional CE and ATEX approved electrical contacts allow the AP Model to double as a pressure switch for alarm or interlock functions, making it a versatile instrument for both indication and control duty across India's process, HVAC and utility sectors.
Key Features at a Glance
- Stainless steel case & measuring system, bayonet-type bezel
- Selectable ranges: -6000 to 6000 mmWC (LP) & -1 to 25 kg/cm² (HP)
- Flanged or screwed process connection
- Dial sizes: 100 mm and 150 mm
- Micrometer zero-adjustable pointer
- IP 65 ingress protection (IP 55 with electrical contacts)
- CE & ATEX approved electrical contacts available
- Wetted parts in SS, PVC, PVDF, PP, Hastelloy C, Monel or Titanium
- GOST-R approval available
- Suitable for clean air and corrosive gaseous/liquid media
Working Principle
Diaphragm deflects under pressure, transmitting motion to the dial pointer via SS movement
Manufacturer
Baumer Group — global sensor and instrumentation manufacturer
Standard
EN 837-3 general requirements for diaphragm pressure gauges
Accuracy
±1.6% of F.S. standard; ±2.5% F.S. with electrical contacts fitted
Protection
IP 65 standard; IP 55 with electrical contacts fitted
Unique Design
Bayonet-type SS case with interchangeable bottom chamber materials for corrosive media
Product Models
LP vs HP — Which AP Model Diaphragm Gauge Fits Your Application?
Both variants share the same steel case construction and EN 837-3 basis. Choose based on the pressure magnitude and measuring precision your application requires.
LP (Low Pressure) Version
For very low, sensitive pressure measurement in mmWC — where a Bourdon tube would lack resolution.
- •Range: -6000 mmWC to 0 & 0 to 6000 mmWC
- •NS 100 mm: 2600g (with box) · NS 150 mm: 3080g
- •Ideal for HVAC ducting, clean rooms & filter monitoring
- •150 mm size required for ±250 mmWC / ±400 mmWC ranges
HP (High Pressure) Version
For general process and chemical pressure measurement where diaphragm isolation is preferred over a Bourdon tube.
- •Range: -1 kg/cm² to 0 & 0 to 25 kg/cm²
- •NS 100 mm: 1560g (with box) · NS 150 mm: 2020g
- •Ideal for viscous, slurry or crystallizing-risk media
- •Broad wetted-material choice for chemical compatibility
Technical Data
Technical Specifications — Baumer AP Diaphragm Pressure Gauge
Full technical parameters as per Baumer datasheet 31-08-12. Zebco Engineering can supply any configuration — contact us for custom dial, connection, or material requirements.
| Parameter | Specification / Options |
|---|---|
| Standard | Standard version: NS 100 mm & 150 mm, general EN 837-3 |
| Diaphragm type — HP | -1 to 0 kg/cm² & 0 to 10 kg/cm² (extendable to 25 kg/cm²) |
| Diaphragm type — LP | -6000 mmWC to 0 & 0 to 6000 mmWC |
| Accuracy | ±1.6% of F.S. (standard) · ±2.5% of F.S. with electrical contacts |
| Ambient temperature | -25°C to +65°C (standard) · Max. 65°C with electrical contacts |
| Process temperature | Max. 100°C (standard) · Max. 65°C with electrical contacts |
| Operating pressure range | 75% of scale value |
| Overpressure limit | 125% of scale value |
| Case & bezel | AISI 304 SS (bayonet type) |
| Top chamber | AISI 304 SS (standard) · AISI 316 SS optional |
| Bottom chamber | AISI 316 SS (standard) · PVC, PVDF, PP, Hastelloy C, Monel, Titanium optional |
| Movement | AISI 304 SS (standard) · AISI 316 SS optional |
| Diaphragm | AISI 316L SS (standard) · Hastelloy C, Monel optional |
| Gauge connection | ½" BSP (M) standard |
| Protection | IP 65 (IP 55 with electrical contacts) |
| Dial | Aluminium, black graduation on white background |
| Pointer | Aluminium, black coloured, micrometer zero adjustable |
| Window | Sheet glass (standard) · Polycarbonate dome (with electrical contacts) |
| Blow-off disc & gasket | Neoprene |
| Approvals | GOST-R; CE & ATEX for electrical contacts |
Temperature effect: variation caused by ambient temperature is added to the specified accuracy per the formula ± 0.08 × (t2 − t1)% of F.S., where t1 = reference temperature (+20°C) and t2 = ambient temperature in °C. Note: adding mechanical electric contacts affects accuracy — e.g. 1% becomes 1.5%, 1.6% becomes 2.4% (add 50% of the base accuracy). For magnetically-assisted contacts, this addition cannot be applied within ±5% of the set point.
Dimensions
Dimensions — Type 2 (Direct Bottom Entry)
Dimensions in mm; drawings not to scale. Weights are approximate for the standard product with box.
| NS | Type | A (mm) | B (mm) | Ø C (mm) | Ø D (mm) | AG* (mm) | AI (mm) | Weight, with box (g) |
|---|---|---|---|---|---|---|---|---|
| 100 mm | LP | 12.5 | 47 | 111 | 100 | 158 | 17.5 | 2600 |
| 150 mm | LP | 15 | 49 | 161 | 149 | 158 | 17.5 | 3080 |
| 100 mm | HP | 12.5 | 47 | 111 | 100 | 98 | 19 | 1560 |
| 150 mm | HP | 16 | 49 | 161 | 149 | 98 | 19 | 2020 |
LP Type = -6000 mmWC to 0 & 0 to 6000 mmWC. HP Type = -1 kg/cm² to 0 & 0 to 25 kg/cm². *For ranges ±250 mmWC and ±400 mmWC, the 150 mm size is required for LP type.
Pressure Ranges
Available Pressure Ranges — AP Model
The Baumer AP Model covers pressure, vacuum and compound ranges in both HP (kg/cm²) and LP (mmWC) formats. National and international scales — kPa, MPa, bar, psi, kg/cm² and dual scales — are available on request.
HP — Pressure Range (Single Scale kg/cm²)
HP — Dual Scale (psi with kg/cm²)
| KG/CM² | KG/CM² | ||
|---|---|---|---|
| 0 / 15 | 0 / 1 | 0 / 100 | 0 / 7 |
| 0 / 30 | 0 / 2 | 0 / 150 | 0 / 10 |
| 0 / 60 | 0 / 4 | — | — |
HP — Vacuum & Compound Range
Single scale (kg/cm²): -1/0.6, -1/1.5, -1/3, -1/5, -1/9. Dual scale (inHg with psi / mmHg with kg/cm²): -30/0 = -760/0, -30/15 = -760/1, -30/30 = -760/2, -30/60 = -760/4, -30/100 = -760/7, -30/150 = -760/9.
LP — Pressure Range (Single Scale mmWC)
LP — Vacuum Range (Single Scale mmWC)
LP — Compound Range (Single Scale mmWC)
| Range | Range | |
|---|---|---|
| -100 / 150 | -400 / 600 | -1000 / 1500 |
| -150 / 250 | -600 / 1000 | -1500 / 2500 |
| -200 / 400 | -800 / 1200 | -2000 / 4000 |
Accessories available: EC gauge cock, needle valve, EG snubber, EH siphon, EB cooling tower, ED overload protector (gauge saver — for ranges 6000 mmWC and above). Refer to the valves & manifolds catalogue for full specifications.
Material Options
Construction Materials & Wetted-Part Options
The AP Model's modular chamber and diaphragm construction lets you match wetted-part material precisely to your process media — from clean air to aggressive chemicals.
Case, Bezel, Top Chamber & Movement
Standard corrosion-resistant construction for the outer case, bayonet-type bezel, top chamber and internal movement — suited to most general industrial environments.
Bottom Chamber & Diaphragm
Standard wetted-part material offering strong resistance to chlorides and general process chemicals. The diaphragm isolates the movement entirely from the process media.
Plastic Bottom Chambers
For highly corrosive or aggressive chemical media where even stainless steel is unsuitable. Pressure rating is derated with rising ambient temperature — refer to the pressure-vs-temperature table for exact limits.
Exotic Alloy Options
For extreme corrosion resistance in specialty chemical, offshore or high-purity process applications, both the bottom chamber and diaphragm can be specified in Hastelloy C, Monel, or Titanium.
PTFE Lining, Coating & Protection
PTFE lining on the flange or screwed connection, PTFE coating or protection on the diaphragm, and a PTFE gasket rated up to 200°C — for additional chemical resistance without a full exotic-alloy upgrade.
Inductive Electrical Contacts
220V AC, 0.4A inductive contacts in single or double configurations, for pressure ranges from 6000 mmWC to 10 kg/cm², with ingress protection up to IP 55 — CE and ATEX approved for hazardous area use.
Electric Contacts
CE & ATEX Approved Electrical Contact Configurations
The AP Model can be supplied with inductive-type electrical contacts (220V AC, 0.4A) for alarm, interlock or shutdown duty — available in single and double contact arrangements. Contact set points must be specified at the time of ordering.
Single — Normally Open (1 NO)
Opens on rising pressure past set point — for high-pressure alarm signalling.
Single — Normally Closed (1 NC)
Closes on rising pressure past set point — for low-pressure alarm or interlock signalling.
Double — NC + NO
Combined normally closed and normally open contacts for dual-threshold alarm logic.
Double — NO + NC
Combined normally open and normally closed contacts, opposite sequencing to YX.
Double — NO + NO
Two independent normally-open contacts for staged high-pressure alarms.
Double — NC + NC
Two independent normally-closed contacts for staged low-pressure alarms or interlocks.
Scale amplitude for contact versions is between 180° and 270°, with a polycarbonate dome window. Applicable for pressure ranges from 6000 mmWC to 10 kg/cm², with ingress protection up to IP 55. Note: fitting electrical contacts increases the gauge's rated inaccuracy — specify set points carefully at order time.
Applications
Where Is the Baumer AP Diaphragm Gauge Used?
The diaphragm sensing element and modular wetted-material options make the AP Model well suited to low-pressure and corrosive-media applications that a Bourdon tube gauge cannot handle as cleanly.
Clean Air Systems
Low-pressure air handling units, ducting and filter differential-pressure monitoring.
Corrosive Chemical Media
Aggressive acids, alkalis and solvents handled via PVDF, Hastelloy or Monel wetted parts.
Gaseous Process Lines
Non-crystallizing gaseous media that must not obstruct the pressure system's internal passages.
Process & Utility Plants
General process pressure indication where diaphragm isolation is preferred for maintenance ease.
HVAC & Cleanrooms
Low-pressure (mmWC) monitoring for HVAC systems, cleanroom pressure cascades and fume hoods.
Alarm & Interlock Duty
Electrical-contact versions double as pressure switches for automated shutdown or alarm signalling.
Slurry & Viscous Media
Diaphragm isolation handles viscous or particulate-laden fluids that would clog a Bourdon tube.
General Industrial
Flanged or screwed connection options integrate easily into existing pipework and tanks.
Chemical & Corrosive Process Industry
Baumer AP Model for Corrosive Media & Low-Pressure Process Monitoring
Corrosive chemical processes and ultra-low-pressure systems both demand something a standard Bourdon tube gauge struggles to deliver: media isolation without sacrificing sensitivity. The AP Model's diaphragm sensing element, paired with its modular wetted-material range, makes it a go-to instrument for India's chemical, pharmaceutical and clean-air process sectors.
Why the Baumer AP Model Is Specified for Corrosive & Low-Pressure Duty
- •Diaphragm isolation: The flexible diaphragm keeps aggressive or particulate-laden media away from the movement, extending service life versus a directly-wetted Bourdon tube.
- •Modular wetted-part selection: Choose AISI 316 SS, PVC, PVDF, Polypropylene, Hastelloy C, Monel, or Titanium bottom chambers to match your exact chemical compatibility requirement.
- •PTFE protection options: Lining, coating, or diaphragm protection in PTFE adds a further layer of chemical resistance without moving to a full exotic-alloy build.
- •True low-pressure sensitivity: LP ranges down to fractions of a mmWC give the resolution needed for cleanroom pressure cascades and HVAC filter monitoring that a kg/cm²-scale Bourdon gauge cannot provide.
- •CE & ATEX contacts: Built-in alarm/interlock switching removes the need for a separate pressure switch in hazardous-area installations.
- •Flanged connection support: DIN, ANSI, BS and JIS flange options integrate directly into existing chemical process piping without adapter fittings.
Typical Chemical & Low-Pressure Applications
Acid & Alkali Handling
Pressure monitoring in corrosive chemical transfer lines using PVDF or Hastelloy wetted parts.
Cleanroom Pressure Cascades
Differential-pressure monitoring between cleanroom zones using LP-range diaphragm gauges.
Fume Hood & Exhaust Systems
Low-pressure ducting monitoring to confirm safe extraction airflow in labs and pharma plants.
Reactor Vessel Monitoring
HP-range diaphragm gauges on chemical reactor vessels handling viscous or crystallizing media.
Alarm & Shutdown Systems
Electrical contact versions integrated into plant interlock and emergency shutdown logic.
Gas Filtration Systems
Filter differential-pressure monitoring on gas purification and filtration skids.
Ordering Guide
How to Order the Baumer AP Pressure Gauge
Ordering code: AP . X . X . XX . XX . XX . XXX . Range . XX . XX — nominal size, mounting type, top/bottom chamber, diaphragm, process connection, range, and optional extras / electrical contacts.
Nominal Size & Mounting
Code F = 100 mm, H = 150 mm. Mounting type 2 = direct bottom entry, type 6 = 2" pipe/yoke mounting with bottom entry.
Chamber Materials
Top chamber: XW (AISI 304 SS, standard) or XY (AISI 316 SS). Bottom chamber: TM (AISI 316 SS, standard), TK, TL, UH, TT, TX, TZ, UA or TY for alternate materials.
Diaphragm Material
UJ (AISI 316L SS, standard), UL (Hastelloy C), or UM (Monel).
Process Connection
4BM ½" BSP(M), 4NM ½" NPT(M) — both standard. 4TM ½" BSPT(M), 4MM M20x1.5(M), 3BM 3/8" BSP(M), or Flanged per the flange table.
Pressure Range
Select from the LP or HP range tables — pressure, vacuum or compound, in mmWC, kg/cm², bar, psi or dual scale.
Optional Extras & Contacts
PW calibration certificate, RH custom dial, RX/RZ safety glass, PS 316 SS case, GH material certificates, plus electrical contact codes YW/YV/YX/ZA/YY/YZ if required.
Why Choose Us
Why India's Industries Trust Zebco Engineering for Baumer Gauges
Zebco Engineering LLP is an authorized Baumer Supplier in India, supplying precision pressure and temperature instrumentation to process, chemical and industrial sectors nationwide.
Authorized Baumer Supplier
100% genuine Baumer instruments with manufacturer documentation and full traceability.
Material Selection Expertise
Technical guidance on wetted-material choice for your exact process media and temperature.
Competitive Pricing
Transparent quotations, bulk pricing for OEMs and EPCs, flexible commercial terms.
Pan India & Global Delivery
Reliable supply across India's industrial zones and export to Middle East, Southeast & South Asia.
Fast Dispatch
Stocked inventory enables short lead times for urgent maintenance and commissioning needs.
Full Documentation Support
Test reports, calibration certificates and material certificates for audit-ready procurement.
Delivery
Pan India & Global Supply
Zebco Engineering delivers Baumer AP diaphragm gauges to every industrial zone in India and internationally to key global markets.
🇮🇳 Pan India Delivery
Supplying Baumer AP diaphragm gauges to India's major chemical, HVAC and process industrial clusters.
🌐 Global Export
International supply with export documentation, commercial invoices and compliance certificates.
FAQ
Frequently Asked Questions
Common questions about the Baumer AP Model diaphragm pressure gauge and how to purchase it from Zebco Engineering in India.
The Baumer AP Model is a steel-case diaphragm-type pressure gauge for low pressure (LP, measured in mmWC) and high pressure (HP, measured in kg/cm²) applications. It measures pressure via diaphragm deflection rather than a Bourdon tube, making it suitable for very low pressures, corrosive media, and gaseous or non-crystallizing liquid media that must not obstruct the pressure system.
The LP (low pressure) version covers -6000 mmWC to 0 and 0 to 6000 mmWC, suited to HVAC, cleanrooms and low-pressure gas systems. The HP (high pressure) version covers -1 kg/cm² to 0 and 0 to 25 kg/cm², suited to general process and chemical lines. Both share the same steel case, diaphragm design and EN 837-3 basis, differing mainly in diaphragm sensitivity and internal chamber sizing.
Standard bottom chamber is AISI 316 SS. For corrosive or specialty media, Baumer offers PVC, PVDF, Polypropylene, Hastelloy C, Monel and Titanium bottom chambers, plus PTFE lining, coating, or diaphragm protection. Pressure rating varies by material and temperature — PVDF/PP/PVC chambers are derated as ambient temperature rises.
Yes. CE and ATEX approved inductive-type electrical contacts (220V AC, 0.4A) are available in single (1 NO or 1 NC) and double contact configurations (NO+NC, NO+NO, NC+NC) for pressure ranges from 6000 mmWC to 10 kg/cm², with ingress protection up to IP 55. Adding electrical contacts affects gauge accuracy — for example 1.6% F.S. becomes 2.4% F.S. — so contact set points must be specified at order time.
Standard screwed connections are ½" BSP(M) or ½" NPT(M), with ½" BSPT(M), M20x1.5(M) and 3/8" BSP(M) also available. Flanged connections are available per DIN 2527/2642/2633/2635, ASME/ANSI B16.5, BS-10, and JIS B2210 standards, in sizes from ½" to 3" and various pressure ratings/classes.
Standard version: ambient -25°C to +65°C, maximum process temperature 100°C. With electrical contacts fitted, both ambient and process temperature are limited to a maximum of 65°C. Bottom chambers in PVDF, PP or PVC are pressure-derated further as temperature increases — refer to the pressure-vs-temperature table.
Yes. Zebco Engineering LLP is an authorized Baumer Supplier in India, supplying pan India to all major industrial zones plus international export to the Middle East, Southeast Asia and South Asia with complete documentation. Contact +91 98982 26321 or sales@zebcoeng.com.
Let’s Get Started
Our team is here to help with all your industrial needs. Reach out to us today, and let Zebco Engi neering provide the solutions you're looking for.
Need Expert Assistance?
Complete the Form and We'll Reach Out Soon!
