Test Methods: ASTM D2112, D2272, IP229

Heated Bath for Rotary Pressure Vessel Oxidation Test RPVOT (RBOT)

  • Liquid Bath from Ambient to 175�C
  • 1, 2, or 4 Position Units
  • Conforms to ASTM D2272, D2112, and IP229
  • Leak-proof arrangement for pressure vessel rotation
  • Precision motor for 100 +/- 1 RPM
  • Data acquisition available
  • Wireless Data Capture Option

The ASTM D2272 RPVOT (formerly known as RBOT) test, and related D2112 and IP229, determine the break point or induction period of an oil sample in the presence of oxygen and a copper catalyst. The sample is placed in a pressure vessel and rotated at a 30º angle and 100 RPM in a high temperature heated oil bath. The number of minutes required to reach a specific pressure drop is the oxidation stability of the sample.

Leak-Proof Arrangement for Pressure Vessel Rotation:

The pressure vessel assembly is angled at the specified 30º angle from horizontal and a speed controlled drive for rotating the pressure vessels at 100 rpm is provided. The Lawler drive mechanisms to rotate the pressure vessels are located above the bath oil level. Thus avoiding the troublesome leaks associated with competitive units with shafts through the bath box, below the liquid level. Additionally the motor and drive mechanism is located in the front of the unit for easier maintenance in the unlikely event of a problem.

A precision DC motor is used for pressure vessel rotation, avoiding AC line voltage fluctuations that lead to speed changes in AC motors. In multi-position units, independent motors are used to limit downtime and provide energy savings.

Our four position unit, Model 472-4, has unique feature of twin two position bath arrangement. Each bath with two positions is fully independent. There are several benefits when running one or two baths:

  • Savings of ageing and oxidation of the expensive high temperature rated bath oil
  • Energy savings
  • Reduced amount of fuming hazardous bath oil vapors
  • Faster heat up time

DAX-OX Data Acquisition System: Data capture for up to 4 positions plus bath temperature

DAX-OX consists of an interface unit and Lawler PC based software. Data is graphed in the PC software and can be imported into a spreadsheet for further analysis. The time for each sample to break is calculated and reported. A very useful feature of the software is the ability to superimpose graphs from previous tests for a convenient detailed comparison. The system is very robust by use of a smart interface that stores the data in non-volatile memory. Should the connection with the PC be lost, the system will store the data until the PC is operational. DAX-OX includes a color touch panel to display pressures and bath temperature so pressure vessel charging and test monitoring can be performed without need of a PC. Touch panel will beep upon completion of a test by breakpoint or user configurable length of time.

Pressure Sensors: Two options are available for sensing the pressure in each pressure vessel.

  • PX Pressure Transducers can be connected to each pressure vessel by means of the RC Rotary Coupling which prevents electrical cord from getting tangled during rotation.
  • Optionally a WPX Wireless Pressure Transducer sender and receiver can be used. The WPX is an optional replacement for PX/RC that eliminates cord management issues.

Available Models & Accessories
Part No.

Single position liquid bath for RPVOT


Two position liquid bath for RPVOT


Four position liquid bath for RPVOT, arranged in twin independent two positions


Oxidation pressure vessel


Glass beaker


Cover for beaker


Spring clip for holding down sample beaker


O-ring for pressure vessel


Copper coil catalyst, pre-wound and supplied in a jar


Data acquisition interface and PC software.


Pressure transducer. 0-200 psig (0-1379 kPa), ºî male NPT connection, 5 ft cable


Rotary coupling for PX


Wireless pressure transducer and receiver. Optional replacement for PX/RC.†Eliminates cord management issues.

Ordering Note: One PX and RC per test position. Or one WPX wireless option per test position

Specifications subject to change without notice. Lawler Manufacturing Corporation © 2011