Samson Type 47-5 Flow and Differential Pressure Regulator

Samson Type 47-5 flow and differential pressure regulator

The Samson Type 47-5 is a self-operated regulator that controls two quantities at once: the flow rate, set at an adjustable restriction, and the differential pressure, set at a fixed value inside the actuator. The valve closes when either the flow or the differential pressure rises, and the larger of the two signals always governs. The datasheet T 3131 covers it together with the Type 46-7 and the Type 47-1 and lists valve sizes DN 15 to 50, PN 16 and 25, liquids up to 150 °C and nitrogen or air up to 150 °C in the PN 25 FKM version. Seven Star LLC supplies the Type 47-5 in Oman and the GCC as an independent supplier in Muscat.

A combined regulator replaces two separate devices, a flow limiter and a differential pressure regulator, with a single globe valve and an actuator with two operating diaphragms. It is aimed at district heating and cooling substations and at industrial plants where each branch needs a defined maximum flow without disturbing neighbouring branches.

Type 47-5, 46-7 and 47-1: what the codes mean

The datasheet describes the 47-5 as the fixed-differential-pressure version with an adjustable flow rate and overload protection. The 46-7 and 47-1 versions allow the differential pressure set point to be changed with a manual adjuster and a scaled cap.

Type 47-5 technical specifications

How the dual control works

Flow is measured as the pressure drop across the adjustable restriction. The low pressure downstream of the restriction passes through a hole in the plug to one diaphragm chamber, and the high pressure is sent by a control line to another, so the second diaphragm turns the flow-related pressure into a force. The first diaphragm turns the differential pressure of the circuit into a second force. The plug follows whichever force is larger, moving in the closing direction when either the flow or the differential pressure exceeds its set point. The minimum differential pressure across the valve is the restriction pressure drop plus the (flow divided by KVS) squared term given in the datasheet.

Where the 47-5 fits in a system

The regulator is placed in the line it protects, normally on the return of a substation or branch. Other Samson regulators on this site that complement it are the Type 46-6 (differential pressure with flow limit), 45-1 N and 42-36 (flow regulator). When the plant also needs temperature control, the Series 43 regulator can be combined in the same branch.

Selection checklist for a Type 47-5

• Required maximum flow and the differential pressure available across the branch.
• Fixed differential pressure set point from 0.2 to 0.5 bar.
• DN and KVS to cover the flow range, noting that noise rises if the listed flow ranges are exceeded.
• PN 16 or PN 25 and the temperature, including FKM seals for oils or gases.
• End connection: welding ends, threaded ends, screw-on flanges or a flanged body for DN 32 to 50.
• Intermediate insulating piece for well-insulated pipes.

Installation, commissioning and maintenance of the 47-5

Horizontal or vertical pipes are acceptable, but DN 32 and larger must be installed in horizontal pipes with the actuator down. Respect the flow arrow and connect the external control line to the correct pipe. A strainer upstream is recommended. During commissioning, adjust the restriction cap to the flow set point using the flow table, then verify with a flow meter. If the flow set point is exceeded, a noise increase can be expected even without cavitation. Maintenance is simple: strainer cleaning, diaphragm inspection and seat checks.

Typical applications of the Type 47-5 in Oman and the GCC

Branch-balancing in chilled-water and heating systems of large buildings, district cooling substations, camp utilities and process heating loops all benefit from a regulator that works without power or signal wiring. Because the actual flow is limited at the source, commissioning of the whole network is much quicker than with manual balancing valves alone.

Information to send with your Type 47-5 RFQ

• Medium, temperature range and operating pressure.
• Maximum flow to be set and the pressure available across the branch.
• Differential pressure set point.
• DN, PN and connection type.
• Any special seal requirement (oil, nitrogen or air).
• Quantity, tags and delivery site.

Documents and quotation

The Samson data sheet T 3131 covering Types 46-7, 47-1 and 47-5 is attached on this page. Send your duty data and we will confirm availability and lead time. Seven Star LLC is an independent supplier and does not claim any official status with the manufacturer.