Rosemount 1199 Diaphragm Seal System
Overview
The Rosemount 1199 diaphragm seal system isolates a pressure, differential pressure or level transmitter from a difficult process. The official data sheet states that Rosemount 1199 seal systems provide reliable process pressure measurement and prevent the process medium from contacting the transmitter diaphragm. They are designed for extreme hot and cold temperatures, corrosive, clogging or viscous processes, hygienic requirements and special process connections, and they apply to level, flow, pressure, interface and density measurement.
As a supplier of Rosemount products in Oman and the GCC, Seven Star LLC supplies the Rosemount 1199 Diaphragm Seal System with the Rosemount 1199 datasheet and regional engineering support. Plants in Muscat, Sohar and Salalah can specify seal and transmitter together so that the fill fluid, diaphragm material and connection are matched and the assembly is delivered filled, tested and calibrated.
Seal System Operating Principle
A diaphragm seal places a flexible metal diaphragm between the process and the transmitter. The cavity behind the diaphragm is filled with a fluid that carries the pressure, directly or through a capillary, to the transmitter sensor. The seal therefore keeps hot, corrosive or sticky media away from the sensing element, and the fill fluid sets the usable temperature range. The data sheet lists silicone 200 from –45 to 205 °C, Tri-Therm 300 up to 300 °C with a capillary or 4 inch extension, and inert halocarbon from –45 to 160 °C, along with hygienic fills such as glycerin and water, propylene glycol and water and Neobee M-20.
The Rosemount 1199 is available in two configurations. A direct mount seal eliminates mounting hardware and minimizes oil volume to improve performance, and suits open or vented tanks. A remote mount seal uses a capillary, available in three diameters to balance accuracy against response time, and is used at the top of a vessel for differential measurement or in high temperature service. Tuned-System assemblies combine a direct mount high side with a remote low side, reducing installation costs by 20 percent, improving performance by up to 30 percent and increasing response time by up to 80 percent compared with balanced capillary systems.
Engineering Design of the Rosemount 1199
The Rosemount 1199 is built as a welded system with no threaded connections and is 100 percent helium leak tested. Two construction options exist. Welded-repairable construction welds every point except the gasket between the sensor module and the transmitter flange, so the transmitter can be reused after repair. All-welded vacuum construction welds the disk over the sensor module isolators and is intended for vacuum applications below 6 psia (400 mbar-a), although the system is then not repairable. Reliable operation in full vacuum is a stated capability.
The connection range covers flush flanged seals in ASME B16.5 from Class 150 to Class 2500 and EN 1092-1 up to PN 160, extended flanged seals, threaded seals, hygienic seals and specialty seals such as saddle, wafer, chemical tee and flow-through types. Diaphragm materials include 316L stainless steel, alloy C-276, tantalum, titanium, duplex stainless steels, alloy 400, nickel 201 and more, with diaphragm thickness options of 0.002 inch and 0.006 inch for abrasive service. Capillary lengths run from 1 foot (0.3 m) to 50 feet (15.2 m), and option QZ delivers a remote seal calculation report covering temperature effects, response time and total probable error.
Key Features
The Rosemount 1199 provides a complete range of seal technologies. The features below are taken from the official data sheet.
- Supports flanged, threaded and hygienic connections that meet ASME, EN, JIS, GOST and ISO standards.
- Offers a variety of fill fluids for cold temperature, hot temperature and hygienic and food grade applications.
- Provides three capillary diameters so engineers can optimize accuracy and response time.
- Offers multiple diaphragm coatings for tough applications including corrosion and hydrogen permeation.
- Uses welded construction that is 100 percent helium leak tested and reliable in full vacuum.
- Protects the seal with backup convolutions and recessed diaphragms that reduce handling damage.
- Carries 3-A and EHEDG Type EL Class I approvals on listed hygienic seals such as the Tri-Clamp style SCW.
- Quantifies total system performance for the transmitter and seal assembly with the QZ option.
Industrial Applications
The Rosemount 1199 is used wherever the process cannot touch the transmitter. Typical uses include high temperature heat transfer oil and bitumen lines, low temperature cryogenic and refrigerated services, corrosive acids, polymer and slurry lines, crystallizing or clogging products, and hygienic duty in food, beverage, dairy and pharmaceutical plants where CIP and SIP cycles require flush-mounted Tri-Clamp or tank spud connections. In Oman, applications include refineries, petrochemical and fertilizer units, desalination chemical dosing, and food and beverage producers in the Sohar and Salalah industrial zones.
In Oman and the GCC, Seven Star LLC supplies the Rosemount 1199 to operators, EPC contractors and maintenance teams across Oman and the wider GCC. The seals attach to the Rosemount 3051 pressure transmitter, the Rosemount 2088 gauge and absolute pressure transmitter and the Rosemount 3051SAL liquid level transmitter, and the 2051 and 3051T families listed in the seal attach-to table.
Technical Specifications
The table summarizes published Rosemount 1199 information from the Emerson product data sheet dated March 2026.
| Parameter | Specification |
|---|---|
| Model | Rosemount 1199 Diaphragm Seal System (direct mount and remote mount) |
| Connection types | Flanged, threaded, hygienic and specialty seals |
| Standards | ASME B16.5, EN 1092-1, JIS B2238, ASME B1.20.1, EN 10226-1, GOST 33259-15, ISO 228-1 |
| Flush flanged sizes | 2, 3 and 4 inch (DN 50, DN 80, DN 100), Class 150 to 2500, PN 10 to PN 160 |
| Fill fluids | Silicone 200, Tri-Therm 300, inert halocarbon, glycerin and water, propylene glycol and water, Neobee M-20 |
| Silicone 200 temperature | –45 to 205 °C |
| Tri-Therm 300 temperature | –40 to 300 °C with capillary or 4 inch extension |
| Capillary length | 1 ft (0.3 m) to 50 ft (15.2 m) |
| Construction | Welded, helium leak tested; all-welded vacuum version for below 6 psia |
| Hygienic approvals | 3-A and EHEDG Type EL Class I on listed seal types |
| Performance report | QZ option for total system performance |
Request a Quote for Rosemount 1199
Request a formal quotation for the Rosemount 1199 Diaphragm Seal System from Seven Star LLC. Send the process fluid, temperature and pressure range, nozzle or connection type, preferred fill fluid, capillary length and the transmitter it must attach to, and our instrumentation division will return a valid model code with lead time. We can share the Rosemount 1199 datasheet and confirm availability and lead time. In Oman and the GCC, Seven Star LLC supplies seal systems on request with the local support that difficult measurement points require.
Related drafts in this range include Rosemount 3051L liquid level transmitter, Rosemount 2051 pressure transmitter and Rosemount 3051T in-line pressure transmitter.
- Datasheet Emerson Rosemount DP Level Transmitters and 1199 Diaphragm Seal Systems Product Data Sheet 00813-0100-4016, Rev UD, March 2026 Download
Rosemount product families on this page
Pressure includes the 3051 in its variants (3051T in-line, 3051L for liquid level, 3051CF DP flowmeter and the 3051SMV MultiVariable transmitter), the 2051 and 1199 diaphragm seal systems. Level instruments are the 3300 guided wave radar, the 5408 non-contacting radar and the 2120 vibrating fork switch. Temperature is covered by the 248 and 644 head mount transmitters and the 848T high density transmitter for multiple sensor inputs. The 8800D vortex flowmeter and the 702 wireless discrete transmitter are also listed, along with liquid analysis sensors.Where Rosemount instruments are used
These are standard instruments in oil and gas production, refining, petrochemical, power and water plants. Typical duties are line and vessel pressure, differential pressure flow across orifice plates, tank and separator level and interface, and temperature measurement on pipes, reactors and rotating equipment.Ordering Rosemount transmitters: what we need
Send the complete model string and the serial number from the nameplate; a photo is ideal. Every character of the string selects something: range, output, materials of the isolating diaphragm and flange, process connection, housing, approval and options. If you are specifying a new point, give the measured variable and span, process fluid, pressure and temperature, connection, output (4-20 mA HART, FOUNDATION Fieldbus or wireless), display and hazardous area approval. For remote seals add flange size, rating and capillary length.Browse Rosemount products by category: Pressure Instrumentation, Temperature Instrumentation, Level Transmitter, Liquid Analysis Sensors, Flowmeters.

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