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Automatic Tank Drain

Automatic Tank Drain
This assembly provides the ultimate protection against priming system shut-down due to water build-up in the receiver. For remote installation and when equipment can't be monitored on a regular daily basis, this is an absolute must. ...more

Purge Control
Automatic Purge Control offers the ultimate vacuum pump protection against moisture build-up in the oil. It reduces maintenance and frequency of oil changes and helps maintain the vacuum pump in peak performance.

Proper sizing of a vacuum priming system is based on the required volume (V) of air to be removed from the suction side piping and the required lift (h) of the water from the reservoir to the centrifugal pump. The required vacuum (P_REQ) to establish a prime is determined from the following simplified formula.

P_REQ = P_ATM - ρ _x g _x h
 

at standard S.L. conditions we have
 

P_REQ (“Hg absolute)= 29.92 - 0.88 x Feet of Lift

On-Demand Priming Systems

    With On-Demand Priming Systems, priming is done before each time a pump needs to start. On-demand priming systems are sized based on being able to establish a prime within a given amount of time (T). To determine the required average system capacity (Q_AVG) in ACFM we use the following formula.

Q_AVG = V x P_ATM x ln(P_ATM/P_REQ) / (T x (P_ATM-P_REQ))

  NOTE: Pressure values are to be in absolute units, volume (V) in Ft³,

time (T) in minutes, and ln is the natural log.

Add 10% to the calculated capacity for a safety factor to cover inward leakage. From the table below, select the appropriate model with a system capacity in excess of that required.

Automatic Priming Systems

    Automatic systems maintain a prime to one or several (Central System) pumps for immediate start-up whenever needed. With automatic priming systems, once the system is primed, minimal vacuum pump capacity is required to maintain the prime. However, the priming system needs to be sized with sufficient capacity to be able to establish the initial prime within an acceptable period of time. Our systems are generally sized to establish the initial prime within 10 to 20 minutes. Once the initial prime has been established, the system automatically maintains a prime state for immediate startup of all connected centrifugal pumps as they are needed.

Proper system sizing for most applications can be determined by using the table below along with the following guidelines:

1. Calculate the total volume of the system including the suction pipe, casing volume of the pumps that needs to be primed, and discharge piping to the stop valve.
2. From the table, select the corresponding model, simplex or duplex, which correlates to your calculated system volume.
3. For priming (5) or more centrifugal pumps, select the next larger primer size.
4. For lifts greater than 15ft. priming times will be longer and you may want to select the next larger primer size. For lifts greater than 25ft. or any special applications, consult with a LYNN engineer for assistance with the proper selection.
    

Receiver tank size shown is the standard size for a particular model. Depending upon the specifics of the application other receiver sizes may be suitable. Contact a LYNN engineer for further assistance with design and selection.

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