RLA / RLVA
Single-Stage Steam Turbine

These rugged, versatile mechanical drive steam turbines are typically used for lube oil
pumps, feed water pumps, fans, and generators for applications from 1 HP (0.745 kW) to
1000 HP (745 kW). The RLA, horizontal orientation, and RLVA, vertical orientation, radial
split casings comply with API 611, have inlet covers with integral steam chests, 360degree arc of admission, and exhaust casings formed by two heavily ribbed castings.

Hand Valves
The multiple hand valve feature allows part load, overload, and minimum inlet/maximum
back pressure control for flexible operation and increased part-load efficiency. The appropriate number of hand valves is determined by steam and operating conditions and application load requirements.

Overspeed Trip System
The overspeed trip actuating mechanism is a bolt-type, spring-restrained weight, positioned in the turbine shaft. At a pre-selected speed the bolt is released to unlatch the
overspeed trip valve and completely stop the turbine.
The overspeed trip valve is a force-actuated, single-seated, piloted positive shutoff that is
independent of the governor valve. It is designed to minimize pressure drop in the open
position and instantly shut off steam when tripped by the overspeed trip mechanism. The
valve can be manually reset against full-line pressure.

Governing Systems
The Woodward TG series, constant speed, oil relay governor is standard equipment for
RLA/RLVA steam turbines. Other governing systems can be supplied if required to meet
operating conditions or NEMA D specifications.

Rotors, Bearings, Sealing Glands

Manual
governor
speed
adjustment

Hand valve

Permanently
lubricated rod
end ball joints

Low friction
carbon
sleeve

Woodward® TG
governor

Snap-acting bolt type trip

Single-disc, two-row Curtis impulse-type wheels, shouldered,
keyed and shrunk to the shaft, prevent wheel
movement throughout the turbine speed
range. Turbine wheels are located
Stainless steel nozzles
between the bearings. Balancing
and vibration testing are in
Single disc wheel shrunk
and keyed to shaft
compliance with the dynamics section of API 611.
Removable split carbon
ring gland housings

Oil ring
lubrication
Cooling water
jackets

Hard
chromeplated
shaft
50,000 hour L-10
life thrust bearing
Stainless
steel
stationary
and rotating
blades

Antifriction bearings are standard on RLA/RLVA turbines
rated for 50,000-hour L-10
life for increased reliability.
Bearings are remote from the
hot casing allowing operation
at higher steam temperatures
without lube oil or water
cooling systems. Split carbon ring sealing glands are
readily accessible and easy
to remove without disturbing
other parts of the turbine.