McCARTNEY LDPE VALVES & PLUNGERS
McCARTNEY LDPE VALVES & PLUNGERS FOR POLY PROCESS SYSTEMS
Reduce Pressure Drop! McCartney RPD Check Valve - High Flow Springless Check Valve for Initiator Pumps
Traditional initiator pump check valve designs have been characterized by significant pressure drop across the inlet checks. This 
pressure drop generally requires about 50 PSI of “suction pressure” to prevent cavitation of the pump with typical initiator fluids.
In recent years, LDPE process changes have led to the use of initiator fluids with significantly higher vapor pressure. In order to keep the process fluids in the liquid phase, high suction pressures and cooling jackets have been utilized. Even with these actions there have still been concerns about potential pump cavitation while operating in high flow rate conditions.
To address these concerns the McCartney RPD initiator check valve design has been developed to dramatically reduce the pressure drop across the valve.
Key Design Features:
• 0.188” ball seat orifice diameter
• High flow ball cage design
• Lightweight ceramic check balls
• All stainless steel components (except check balls)
• Ball return springs not required
• Will run in either horizontal or vertical orientation
• Direct replacement for previous McCartney designs
(no piping modifications required)
Manual Angle Stop Valve
The McCartney Angle Stop Valve is used to direct the flow of ethylene gas or polyethylene/ethylene gas mixture to various locations of the LDPE Process. This valve is used to stop the flow up of product at pressures from 25,000 to 50,000 psi.
Dual Let Down Valve and Vent Valve
This unique design configuration combines the Product and Vent Valve, allowing for a very compact and efficient valve package. The dual valve design reduces the length of “dead leg” gas to an absolute minimum, greatly reducing related problems such as gas degradation in that area.
The Let Down body mounts directly to an Autoclave Reactor discharge or it can be spooled to the Tubular line. Each of the mounting methods provide equally superb performance.
Each of the two valves is equipped with Bafco Inc™. Electropneumatic Actuators, insuring quick opening of the Vent and precise stem position on the Let-Down Valve.
A complete hydraulic power unit is available along with field manifolds to insure long and dependable service. Standard material for pressure-containing components such as body and inlet adapter is alloy steel forged to the special McCartney specification #43-72. This superior material has provided long and dependable service with exceptional resistance to fatigue failure for nearly 30 years.
Each customer’s specific needs are considered in the valve trim design, including geometry and materials. Special attention is given to potential corrosion and erosion problems in the trim area. Each of the two valves can be configured to meet a customer’s specific process, mechanical, and material requirements.
All McCartney valves can be custom designed for pressures up to 60,000 PSI (4.138 Bar).
High Speed Vent Valve
The McCartney High Speed Vent Valve combines the 2-piece McCartney vent valve design and pneumatic actuator with external manifold and oversize solenoid valve.
The unique pneumatic actuator design allows for “stacking” of the 12” diameter pistons up to a total of six, reducing spare parts inventory.
Optional manual lock is available, providing an additional measure of safety during maintenance. Standard material for pressure containing components such as body and inlet adapter is alloy steel forged to the special McCartney specification #43-72. This superior material has provided long and dependable service with exceptional resistance to fatigue failure for nearly 30 years. The McCartney valve can be configured to meet a customers specific process, mechanical, and material requirements.
Valve assemblies can be custom designed to meet specific operating requirements for pressures up to 60,000 PSI (4.138 Bar).
Process Control Valves (PCV)
The McCartney PCV is a modern design of the Fisher CZA industry workhorse. This valve is dimensionally interchangeable with valves in service today.
The internal configuration is a McCartney stem and seat design. High wear resistance and high corrosion resistance was a prime consideration during the design of the PCV. Simple, robust construction has fewer parts and is more easily refurbished than other valves.
The two-piece body design was chosen to ensure less maintenance while an even higher reliability will be achieved. Routine maintenance can be done easily by on site staff.
A very specialized alloy steel material, forged to McCartney #43-72 specifications, was chosen for its workability and high-pressure performance. A 15-5PH stainless steel option is available when corrosion is a problem. Seat material is nitrided for increased life and corrosion resistance during service in your toughest applications. There is no cage to remove as part of a valve rebuild.
The PCV can be fitted with a variety of actuators. Bafco™ electrohydraulic actuators take full advantage of the sophisticated process control systems in use today. McCartney pneumatic piston type and saginaw style actuators can also be used. We will be happy to consider other actuator options upon request.
Positive Position Process Control Valve
The McCartney Positive Position Process Valve incorporates the Limitorque™ L120 Series electric 
motor driven gear actuator. This robust McCartney/Limitorque™ combination eliminates unintended valve cycling and provides dependable service day after day under the most demanding conditions. The L120 actuator is available in weatherproof and explosionproof configurations. An internal clutch provides dependable control of stem load to greatly reduce the possibility of damage to the stem and seat due to overloading. Handwheels are furnished for manual operation in the event of power failure. The de-clutch lever is padlockable in the motor position.
Standard material for pressure containing components such as body and inlet adapter is alloy steel forged to the special McCartney specification #43-72. This superior material has provided long and dependable service with exceptional resistance to fatigue failure for nearly 30 years. The McCartney valve can be configured to meet a customers specific process, mechanical, and material requirements.
Valve assemblies can be custom designed to meet specific operating requirements for pressures up to 60,000 PSI (4.138 Bar).
Check Valves & Gear Driven Valves
Manual Gear Actuated Valve
All McCartney designed valves are available with 3:1 or 6:1 ratio gear actuators. Housings are made of steel, precisely machined internally to accept precision steel drive and pinion gears. Bronze bearings provide smooth operation of the hand-wheel and actuator stem. The actuators are capable of producing stem loads up to 50,000 lbs. (22.700 kg) with a hand-wheel torque of 100 ft-lbs. or less.
Valve configurations including angle and parallel flow are available, each being designed and manufactured to meet specific customer requirements.
Standard material for pressure-containing components such as body and inlet adapter is alloy steel forged to the special McCartney specification #43-72. This superior material has provided long and dependable service with exceptional resistance to fatigue failure for nearly 30 years. The McCartney valve can be configured to meet a customer’s specific process, mechanical, material requirements, and custom designed to meet specific operating requirements for pressures up to 60,000 PSI (4.136 bar).
Inline Poppet Check Valve
McCartney’s new poppet check valve was designed to address the “hot check” problem common to many hyper compressor lubrication systems. Other applications include initiator delivery lines and reactor entry points. The new valve offers a larger contact surface, which provides a more positive seal while resisting the inclination to brinell at the point of contact. The new internal design positions the spring around the outside diameter of the poppet guide.
This provides the spring with extra support while allowing flow to move around and not through the spring. The use of 15-5PH stainless steel material for the bodies, seat, and poppet guide provide excellent resistance to fatigue, corrosion, and fluid contamination. Extensive testing indicates this combination extends the service life 4 – 10 times over that of a conventional ball and seat design. Inlet and outlet connections are available in standard 9/16”, 1/4” and 3/8” HP sizes. Special connection designs are available upon request. Design Criteria: 60 GPH (227 l/hr) at 60,000 PSI (4.136 bar).
Block Check Valve
The McCartney Block Check Valve is a poppet design in-line valve available with removable seat. Standard material for pressure containing components such as the valve body and inlet/outlet adaptor is alloy steel forged to the special McCartney specification #43-72. This superior material has provided long and dependable service with exceptional resistance to fatigue failure for nearly 30 years. Internal components including the poppet, poppet guide, and removable seat are made of AISI 4340.
Block Check Valves can be configured to meet specific process, mechanical, and material requirements for pressures up to 60,000 PSI (4.136 bar).
Plungers
McCartney has full carbide plunger fabrication capabilities to grind and finish a wide variety of plungers from 250” – 4.00” (6.4 mm – 101 mm). Using Ke-nametal™ carbide blanks, we commonly grind and polish plunger OD surfaces to 1-2 RMS finish.
We also provide O.D. regrind and polish service for worn plungers of all sizes.
