Emerson Rosemount 1595

Emerson Rosemount 1595

1. Introduction to the Rosemount 1595 Conditioning Orifice Plate

The Rosemount 1595 Conditioning Orifice Plate is a precision-engineered primary element designed for accurate flow measurement of liquids, gases, and steam across a wide range of industrial applications-. Unlike conventional orifice plates that suffer from performance degradation in disturbed flow profiles, the 1595 incorporates a patented 4-hole design that actively conditions the flow as it passes through the plate, enabling accurate measurement even in challenging piping configurations-22.

The Rosemount 1595 operates on the fundamental principle of differential pressure measurement, where the restriction created by the orifice plate generates a pressure drop proportional to the square of the flow velocity. This pressure differential is captured through precisely located pressure taps and converted by a DP transmitter into a standardized flow measurement-9.

For professionals requiring a compact, high-performance DP flow solution, the Emerson Rosemount 1595 conditioning orifice plate consistently delivers reliable results. The 1595 conditioning orifice plate can be used with Rosemount 1496 Orifice Flange Unions and Rosemount 1497 Meter Sections, providing a complete, integrated measurement system-1. The 1595 conditioning orifice plate from Emerson Rosemount eliminates the need for impulse lines, special flanges, or piping modifications, significantly reducing installation complexity and cost-22.

2. Technical Specifications

2.1 Operating Parameters

The Rosemount 1595 conditioning orifice plate offers an exceptionally wide operating temperature range from -320°F (-196°C) to 1200°F (649°C), making it suitable for both cryogenic and high-temperature process applications-9. The Rosemount 1595 conditioning orifice plate from Emerson Rosemount is rated for maximum operating pressures up to ANSI Class 2500#, ensuring compatibility with high-pressure process environments. For cryogenic applications where temperatures reach -310°F (-190°C) with density variations in nitrogen, argon, and oxygen fluids, the Rosemount 1595 conditioning orifice plate is the ideal solution-22. The Rosemount 1595 conditioning orifice plate is available in standard line sizes from 2 to 24 inches (50 to 600 mm), with custom sizes offered for application-specific requirements-11.

2.2 Flow Coefficient Uncertainty (Discharge Coefficient)

The Rosemount 1595 conditioning orifice plate meets rigorous flow measurement standards with published discharge coefficient uncertainty values:

For β = 0.65 with Reynolds number (ReD) below 10,000, an additional 0.5% is added to the Discharge Coefficient Uncertainty-1.

2.3 Process Wetted Materials

The Rosemount 1595 conditioning orifice plate offers multiple material options to suit diverse process conditions:

The Rosemount 1595 conditioning orifice plate provides 316/316L stainless steel, Alloy C-276, and Alloy 400 as standard process wetted material options-49. The Rosemount 1595 conditioning orifice plate is manufactured to exacting standards, ensuring material compatibility across a broad spectrum of industrial fluid applications.

2.4 Warranty Information

The Emerson Rosemount 1595 conditioning orifice plate comes with a limited warranty period of up to 5 years-9.

3. Patented 4-Hole Design Technology

The defining innovation of the Rosemount 1595 Conditioning Orifice Plate is its patented 4-hole design. Traditional orifice plates with a single concentric bore are highly susceptible to flow profile distortions caused by upstream disturbances such as elbows, tees, reducers, or partially open valves. These distortions introduce significant measurement errors that can compromise process control and product quality.

The 1595 conditioning orifice plate solves this problem by incorporating four equally spaced orifices that actively condition the flow profile as it passes through the plate-22. This unique configuration enables the Rosemount 1595 conditioning orifice plate to deliver accurate, repeatable results even in severely turbulent flow conditions where conventional DP primary elements would fail-22. The Rosemount 1595 conditioning orifice plate’s patented 4-hole design represents a fundamental breakthrough in DP flow measurement technology, providing unprecedented flexibility in primary element placement without sacrificing measurement integrity.

This innovative design allows the Rosemount 1595 conditioning orifice plate to resolve irregular flow profiles that typically cause swirl and asymmetry in the flow stream, transforming them into a stable, conditioned flow pattern conducive to precise differential pressure measurement-.

4. Minimal Straight Pipe Run Requirements

One of the most significant advantages of the Rosemount 1595 Conditioning Orifice Plate is its dramatically reduced straight pipe run requirement. Conventional orifice plates typically require 10 to 20 diameters of straight pipe upstream and 5 diameters downstream to achieve rated accuracy—a limitation that often forces expensive piping modifications or precludes installation entirely in space-constrained facilities.

The Rosemount 1595 conditioning orifice plate requires only two pipe diameters (2D) upstream and 2D downstream of straight pipe run, a reduction of up to 90% compared to conventional orifice plates-22. The Rosemount 1595 conditioning orifice plate from Emerson Rosemount eliminates the need for separate flow conditioners and extensive piping modifications, dramatically simplifying installation in retrofits and tight-fit applications-22.

Straight pipe requirements for the Rosemount 1595 conditioning orifice plate vary by beta ratio and disturbance type:

Note: Not applicable for line sizes greater than 24 inches (600 mm) for swirl disturbances-2

This minimal straight-run requirement makes the Emerson Rosemount 1595 conditioning orifice plate the ideal choice for applications with limited piping length, such as compressor stations, offshore platforms, skid-mounted systems, and retrofit installations where existing pipe configurations cannot be altered.

5. Installation Guidelines

5.1 Pressure Tap Orientation

Proper orientation of pressure taps is critical for optimal performance of the Rosemount 1595 conditioning orifice plate. The pressure taps must be centered between any two of the four orifice bore holes. Additionally, the pressure taps should be located at 90° to the plane of the last elbow-2. The Rosemount 1595 conditioning orifice plate requires careful attention to this orientation specification to ensure maximum measurement accuracy.

5.2 Centering Requirements

The Rosemount 1595 conditioning orifice plate must be installed so that it is centered in the pipe as recommended by ISO-5167-2. The Rosemount 1595 conditioning orifice plate incorporates self-centering mechanisms that ensure optimal accuracy while improving the overall installation process-22.

5.3 Installation Procedure

The Rosemount 1595 conditioning orifice plate is available in both paddle and universal plate styles. For the Rosemount 1595 conditioning orifice plate, follow these installation steps:

Depressurize the line using site-specific requirements

Loosen all studs and nuts

Remove the studs in one-half of the flange union

Spread the flange union by turning jackscrews clockwise

For line sizes greater than 24 inches (600 mm), refer to alignment tool instructions

Install the new plate or remove the existing plate

Retighten the flange union-2

5.4 Horizontal Pipe Orientation

For gas flow in horizontal pipes, the Rosemount 1595 conditioning orifice plate should be installed with pressure taps positioned at the top. For liquid or steam flow in horizontal pipes, the pressure taps should be positioned at the bottom-2.

5.5 Vertical Pipe Orientation

For the Rosemount 1595 conditioning orifice plate installed in vertical pipes, pressure tap orientation must consider the fluid phase and flow direction to ensure proper measurement-2.

6. Performance Characteristics

6.1 Accuracy

When paired with compatible multivariable transmitters such as the Rosemount 3051S MultiVariable™, the Emerson Rosemount 1595 conditioning orifice plate can achieve measurement accuracy of ±0.05% of reading for enhanced flow calculations-54. The Rosemount 1595 conditioning orifice plate utilizes Callendar-Van Dusen sensor matching technology to improve temperature accuracy, enabling best-in-class fully compensated flow calculations-54.

6.2 Repeatability

The Rosemount 1595 conditioning orifice plate delivers highly repeatable measurement results across the full operating range. Laboratory testing procedures for the Rosemount 1595 conditioning orifice plate typically involve runs conducted at 10 different flow rates, approximately equally spaced from maximum to minimum flow rates, to verify run-to-run repeatability performance-. The Rosemount 1595 conditioning orifice plate consistently provides accurate and repeatable results downstream of various flow disturbances that normally cause swirl in the process flow-.

6.3 Turndown Ratio

The effective turndown ratio of a DP flow measurement system incorporating the Rosemount 1595 conditioning orifice plate is determined largely by the associated transmitter. When paired with the Rosemount 3051S MultiVariable transmitter, the Rosemount 1595 conditioning orifice plate system achieves rangedown capability up to 200:1-54.

7. Sizing and Configuration

The Rosemount 1595 conditioning orifice plate is sized using the Rosemount Instrument Toolkit sizing program, which provides accurate flow calculations using installation details and fluid properties-. A Configuration Data Sheet (CDS) is required prior to order for application verification to ensure the Rosemount 1595 conditioning orifice plate is properly specified for the intended process conditions-1.

8. System Integration

The Rosemount 1595 conditioning orifice plate is designed for seamless integration with Rosemount DP transmitters, manifolds, and flange unions.

8.1 With Rosemount 3051S MultiVariable™ Transmitter

When paired with the Rosemount 3051S MultiVariable™ transmitter, the Rosemount 1595 conditioning orifice plate creates a fully compensated mass flow measurement system. This combination provides:

Measurement of multiple variables (differential pressure, static pressure, process temperature)

Built-in flow calculations for direct reporting of fully compensated mass, energy, or volumetric flow

Elimination of stacked transmitters and additional wiring

Reduced pipe penetrations and impulse piping

8.2 With Rosemount 1496 Orifice Flange Unions

The Rosemount 1595 conditioning orifice plate can be used with Rosemount 1496 Orifice Flange Unions, which:

Position orifice plates appropriately for reliable flow and accurate measurement

Feature threaded tap connections that eliminate on-site drilling

Are supplied with all necessary hardware for straightforward installation

Are available in line sizes up to 24 inches (600 mm)

8.3 With Rosemount 4088 MultiVariable™ Transmitter

For Modbus-based systems, the Rosemount 1595 conditioning orifice plate integrates with the Rosemount 4088 MultiVariable™ transmitter, which enables multivariable measurements in combinations of differential and static pressure and temperature, with rangedown up to 100:1-9.

9. Applications and Industry Use Cases

9.1 Oil and Gas Production

The Rosemount 1595 conditioning orifice plate is widely used in upstream oil and gas applications where space constraints and turbulent flow conditions are common. The optimized sensor technology of the Rosemount 1595 conditioning orifice plate captures large fluctuations in flow rate that typically occur in oil and gas production environments-9.

9.2 Mining and Metals

In a documented mining application, a South American mining company utilized the Rosemount 1595 conditioning orifice plate to measure airflow from blowers in a copper smelting process. The installation had only 2.5 diameters of straight pipe downstream of a 90° elbow—insufficient for conventional flow meters. The Rosemount 1595 conditioning orifice plate achieved ±0.5% accuracy with only 2D upstream and 2D downstream straight pipe runs, significantly reducing material, labor, and procurement costs compared to the previously installed venturi flow meter-26.

9.3 Cryogenic Applications

The Rosemount 1595 conditioning orifice plate is ideal for cryogenic applications, including the transfer of liquefied air gases. The straight run available in trailers for cryogenic transfer is typically very small, making the minimal straight-run requirement of the Rosemount 1595 conditioning orifice plate a critical advantage-22.

9.4 Power Generation

The Rosemount 1595 conditioning orifice plate is used in power plants for main steam line flow measurement, helping reduce maintenance and energy costs while providing reliable performance in high-temperature, high-turndown applications-.

9.5 Refining and Petrochemical

The Rosemount 1595 conditioning orifice plate is suitable for a wide range of refining applications, including flare gas measurement, feed stock flow monitoring, and product transfer lines. The ability to install the Rosemount 1595 conditioning orifice plate in existing piping without modifications significantly reduces project costs and downtime.

9.6 HVAC and Air Handling

For large duct airflow measurement, the Rosemount 1595 conditioning orifice plate provides a cost-effective solution that reduces utility costs while maintaining measurement accuracy in challenging duct configurations-.

10. Comparison: Rosemount 1595 vs. Conventional Orifice Plates

The Rosemount 1595 conditioning orifice plate dramatically reduces installation complexity and cost while maintaining superior measurement performance in challenging flow conditions-9.

11. Maintenance and Service

The Rosemount 1595 conditioning orifice plate is designed for low-maintenance operation. Routine maintenance primarily involves periodic inspection of the orifice plate for wear or damage and verification of pressure tap integrity. For the Rosemount 1595 conditioning orifice plate, removal of pressure and draining of the pipe assembly are required prior to installing or removing the orifice plate-.

The Rosemount 1595 conditioning orifice plate has undergone comprehensive testing, including mechanical and structural testing, in-house performance testing, and independent laboratory testing