Dekker Vmax - User Manual

The DEKKER Vmax oil-sealed liquid ring vacuum pump system is designed to provide safe, reliable, and trouble-free service, offering advantages over other vacuum pump systems due to the absence of metal-to-metal contact between the impeller and casing. This design means the pump requires no internal lubrication. The system utilizes grease-lubricated bearings mounted externally to the pumping chamber, isolated by mechanical shaft seals. Operators must exercise good judgment and follow proper safety procedures during installation, start-up, and operation.

Function Description

The Vmax system operates on the principle of a liquid ring vacuum pump, known for its simplicity and low maintenance requirements. The impeller assembly is the sole moving part, rotating freely within the casing without metal-to-metal contact. The sealing liquid creates a liquid piston action, generating vacuum and removing the heat of compression. This seal fluid circulates in a closed loop, passing through an air- or water-cooled heat exchanger that dissipates the heat. The discharge separator/reservoir holds the seal fluid and incorporates a high-efficiency separator arrangement to separate the seal fluid from the air or gases discharged by the pump.

For systems equipped with a Variable Frequency Drive (VFD) and an Operator Interface Module (OIM) remote keypad, the VFD controls the motor's RPM to maintain a desired vacuum level. In Manual Mode, the system runs at a constant RPM. In Auto Mode, the system monitors a set point configured by the operator via the OIM, adjusting the motor's RPM to achieve and maintain the target vacuum level. The OIM displays real-time data such as total run hours, Torr set point, Torr feedback, horsepower, AMPS, and Hertz.

The system includes various protective devices to prevent damage and aid in maintenance. A High Temperature Switch signals when the oil temperature exceeds a shut-down level, automatically shutting down the unit until the alarm is reset and the temperature drops. An optional High Back-pressure Switch indicates when the exhaust filter element needs replacement, signaling a pre-determined pressure level (e.g., 4 psi) in the separator discharge. An optional Low Oil Level Switch triggers a shut-down if the seal fluid level drops too low.

For multiplex systems, "Automatic alternation" ensures equal operating time among pumps by alternating the lead pump role. "Frequent stop/start protection" allows pumps to operate for a minimum duration (factory-set at 10 minutes) to prevent premature coupling failure and electrical component breakdown, even if the vacuum demand is met sooner.

Usage Features

Installation requires careful attention to location, mounting, and piping. The unit should be installed in a well-ventilated, dust-free area, at least 3 feet from surrounding walls for servicing. The foundation must be level, rigid, and substantial enough to absorb vibrations and support the total unit weight, with larger systems (over 40 HP) requiring grouting. Inlet piping should be at least the size of the pump inlet, with a temporary screen installed at start-up to protect against debris. A 10-micron inlet filter is recommended for dusty or particle-laden gases. A vacuum relief valve (anti-cavitation valve) is essential to prevent damage if the pump inlet becomes closed during operation. Discharge piping should be at least the size of the separator discharge, leading outside to prevent hazardous vapor accumulation.

For water-cooled systems, an adequate supply of cooling water (max 85°F, min 20 psig) is necessary. An optional automatic temperature control valve on the heat exchanger outlet regulates cooling water flow to maintain the system operating temperature between 140°F and 185°F.

Start-up procedures involve ensuring the seal fluid isolation valve is open, checking motor rotation (clockwise from the drive end), and verifying drive coupling alignment for non-monoblock units. For V-belt drives, proper belt tensioning is crucial to prevent premature wear and slipping. The seal fluid level in the separator reservoir must be at the FILL LINE on the sight gauge, with fluid added if necessary. After a brief run, the fluid level should be rechecked. Discharge pressure on the separator gauge should not exceed 2 psig under vacuum conditions, indicating proper discharge pipe system function.

Electrical preparation involves checking incoming voltage against system voltage and verifying proper motor rotation. If rotation is incorrect, two of the three main power leads on the contactor must be switched. All wiring must comply with OSHA, National Electric Code, and local codes, with a main disconnect switch recommended between the vacuum system and incoming power.

The system's operation can be managed via HAND-OFF-AUTO selector switches. In HAND mode, pumps start immediately and run continuously unless an alarm is triggered. In AUTO mode, pumps operate based on vacuum switches, which are typically set with a differential and offset for multiplex systems to ensure efficient operation and load sharing.

Maintenance Features

The Vmax system is designed for minimal maintenance, with service gauges alerting operators when attention is needed. Before any maintenance, all power must be disconnected from the system.

Bearing lubrication for the pump varies by model. Titan-series single-stage pumps (.25-20 HP) have sealed bearings requiring no field lubrication. Larger Titan-series pumps (25-100 HP) and two-stage pumps (2-60 HP) require lubrication every 3000 hours, with grease fittings located on top of each bearing housing. Maxima-K series pumps require lubrication every 1500 hours. Motors (where required) also have a lubrication schedule, typically every 6 months to 3 years depending on speed, frame size, and operating conditions, using high-temperature lithium-based grease.

Inlet filters (if installed) should be checked after the first 8 hours of operation and cleaned or replaced every 1000 to 3000 hours, or more frequently if excessive pressure drop is observed. Care must be taken to prevent foreign material from falling into the pump suction opening.

Seal fluid is crucial for performance and warranty. DEKKER Vmaxol seal fluid is recommended, with Standard Vmaxol requiring changes every 10,000 hours or annually, and Synthetic/Food grade Long-life Vmaxol every 15,000 hours or annually. Fluid changes involve draining the reservoir, pump, and heat exchanger at operating temperature, then refilling to the shaft centerline level. Overfilling the pump above the shaft centerline can cause damage. The seal fluid level should be checked every 500 hours for water build-up.

Devarnishing is recommended to maintain seal fluid quality. DEKKER offers Proclean 39V devarnishing compound for this purpose. Varnished pumps are not covered under warranty.

The seal fluid strainer should be cleaned after the first 50 hours of operation and then every 1000-3000 hours, or if excessive oil discharge temperature (above 185°F) indicates low oil flow.

Spin-on oil filters (if installed) should be changed if the operating temperature steadily increases. Separator elements, located in the separator reservoir, should be replaced every 10,000 hours or annually, or sooner if back-pressure exceeds 4 psig. The transparent oil return lines from the separator should be checked for blockage and replaced if necessary.

Mechanical shaft seals are fitted on all DEKKER pumps and do not require maintenance unless there is significant leakage (more than one drop per minute). Minor "weepage" (less than one drop per minute) is normal and not covered under warranty. Leakage due to abrasive particles or wear and tear is also not covered. Seal replacement instructions are model-specific and require factory consultation.

A comprehensive maintenance schedule includes:

First 8 hours: Check oil level, inlet filter, strainers, temporary inlet screen, water in sight gauge, and piping for leaks.
500 hours: Repeat 8-hour checks.
1000 hours: Check separator element back-pressure (replace if over 4 psig), discharge pipe system for blockage, clean/replace inlet filter, and remove debris from pump housing, motor fan guard, and heat exchanger.
1,000-3,000 hours: Grease bearings with #2 quality lithium grease (3-4 pumps with a grease gun under normal conditions).
10,000 hours (or annually): Change seal fluid, separator element, check coupling element for wear, and clean strainer.
30,000 hours (or every 5 years): Replace mechanical seals and bearings as preventative maintenance by an authorized technician.

Dekker Vmax Specifications

General

Capacity	Varies by model
Horsepower	Varies by model
Max Flow Rate	Varies by model
Max Head	Varies by model
Power	Electric
Voltage	Varies by model
Frequency	50/60 Hz
Inlet/Outlet Size	Varies by model
Weight	Varies by model