The SENTINEL VACUUM CONTROLLER is a diaphragm operated pneumatic valve. With proper installation, it is capable of maintaining a stable vacuum with +- (plus/minus) .2" Hg. over an adjustable range of 10'' - 15" Hg. at the regulator.

The SENTINEL VACUUM CONTROLLER has been designed to correct several serious faults inherent in other types of regulators.

1. The SENTINEL is not load sensitive. It may be adjusted to a desired vacuum level with or without the milking units on the line. This is particularly valuable to the dairyman who milks with a varying number of units. As each unit is removed or added to the system, the Sentinel will automatically compensate for the changing load. In areas where testing devices are used, no readjustment is necessary to correct for the additional load of the units on the pipeline. However, it cannot offset the pressure drop which occurs in the claw due to the weigh device being in series with the milk hose on each unit.

2. The SENTINEL has a fully open to a fully closed span of .2" Hg. This means that when the vacuum rises or falls more than .2'' Hg. the regulator will open to maximum or close. It is not unusual to see most weight type regulators still admitting air into the system although the vacuum level has fallen 2 or more inches.

3. The SENTINEL will return to its set-point within .l" after a drop in vacuum level caused by a leak into the system.

4. The SENTINEL is easy to adjust. It may be set within .l" Hg of the desired level with a special wrench supplied with each regulator. This key is designed to prevent unauthorized personnel from changing the vacuum level, without the owner's consent.

5. SENTINEL VACUUM CONTROLLERS never completely shut off, therefore, a small amount of air is always passing through the unit, even when the poppet is in the closed position. The reason for this air pass-by is because of the .003 clearance between the poppet and the body of the unit. This clearance is necessary to minimize friction, thereby allowing instantaneous reaction to changes in vacuum levels. The amount of air that passes by the poppet is called air pass-by and amounts to approximately 10 CFM in the Model 100, 15 CFM in the Model 350 and 25 CFM in the Model 500.

6. Filter gauges (standard with models 500, 350 and 100, part #348-12) indicate the condition of vacuum controller filters. When the button on the filter gauge pulls in flush with the face, the filter should be changed for dependable operation.

OPERATING PRINCIPLE
(Refer to Figure #1)

As vacuum is applied on first system start up, a vacuum is drawn on the bottom side of the diaphragm (348-9), through the main sensing port located in the bottom of the poppet shaft. The regulator is biased at approximately 3.0" Hg. via the spring (348-3). The vacuum is drawn into the dome (348-11) through the hole in the diaphragm. Once the desired set point is reached, the bellows assembly (348-35) admits air into the dome through dome filter assembly (348-36) and felt filter (348-15), passing through the regulating seat in bellows assembly into the dome (348-11) thus maintaining a constant vacuum in the dome. This vacuum is 3.0'' Hg. below the regulating point of the controller. EXAMPLE: Controller set at I0'' Hg, thus giving 13.0'' Hg. regulating point. At this point the diaphragm is in a balanced condition. Any rise in vacuum will move the diaphragm (348-09) in a downward direction thus opening the valve wider. Any drop will move the diaphragm toward the dome, causing the valve to close. Since the resistance of the moving assembly is very low, a fully open to fully closed range of ± .2” Hg may be obtained.

Figure #1

MOUNTING INSTRUCTIONS

1. The SENTINEL VACUUM CONTROLLER should be mounted at approximately eye level for maximum ease of periodic servicing (changing filters when required). Avoid, whenever possible, mounting close to hot water heaters and vacuum pumps, especially in small engine rooms or confined areas with poor ventilation.

2. Install as close to sanitary trap as possible if maximum control is desired. A tee with an automatic drain on the bottom should be provided to insure drainage after wash-up.

3. Avoid mounting on reserve tanks or headers whenever possible. In some cases this can result in a pipe-organ effect and cause an oscillation or pulsing problem. If this is encountered, a double elbow or offset may be necessary to break up direct airflow beneath the regulator. In some cases placement in a different location may be required. For best results mount the Model 100 with a 2" elbow below it and mount the Model 350 and Model 500 with a 3" elbow below it. For example, when mounting a Model 350 on a 4" vertical line, first place a 4" to 3" conversion T in the line, then come out with 6 to 12 inches of 3" pipe, then place a 3" - 90 degree elbow, add approximately 3 to 6 inches of 3 inch line upwards, place the inlet adapter, then attach the bottom of the Model 350 with the quick disconnect clamp to the inlet adapter.

If you are mounting a Model 350 or Model 500 on a horizontal line between two receiver groups, place a T similar as above, on its side, in the middle of the line separating the two receiver groups. Then add a 6" piece of horizontal pipe, then place a 3" elbow pointing upwards, then add 3 inches of 3" pipe and then add the inlet adapter.

4. It is not necessary to use a pipe wrench to tighten the regulator to the line. A small amount of pipe dope or Teflon tape should be used before installation to provide a seal and prevent galling.

5. Do not reduce the pipe-size the regulator is mounted on to a size less than the diameter of the regulator base, unless the entire system's pipe size is smaller in diameter than the diameter of the regulator base. EXAMPLE: On the model 100, do not reduce below 1 1/2" NPT.

6. At no time should any type lubricant be applied to the regulator (especially WD40). Such lubrication will only cause a collection of foreign particles, restricting movement and eventually destroying the silicone rubber diaphragm.

7. At the time of installation, the customer should be instructed in the adjustment and filter replacement procedure. If the customer is not under a regular service program with his dealer, he should be shown the procedure for cleaning and routine care.

8. Adjustment of desired vacuum level is simply made with the special steel wrench provided with each regulator. Follow these steps: (A) Remove the snap-on top dome filter. (B) Looking down from the top, insert the adjusting wrench in the center of the piece on the top of the dome. (C) Clockwise rotation of the adjusting screw will raise the level, counter clockwise will lower the setting.

9. Upon initial starting of the vacuum pump, the regulator will open fully and then gradually begin to close until its set-point is reached. It is recommended that all drains and valves be closed before system start-up. If too many leaks into the system are permitted and the pump cannot pull at least 8" Hg., the regulator may remain open. The filter gauge provided on Models 500, 350 and 100 has a black button an its face. This button will pull in flush when it is time to change filters. The regulator will automatically correct for filter restrictions of up to 30" H20. But beyond this point sufficient air cannot be taken in to keep vacuum levels down to the desired point.

10. The filter retaining ring must be checked periodically to insure a firm seal. New filters tend to take a cold set and become loose. If this occurs, dirt and foreign particles will by-pass it and become lodged on the moving parts. This may cause sluggish or erratic regulation. It is recommended that each time the filter is changed, the bottom half of the unit below the flange (348-08 Model 350/500, 353-02 Model 100) be washed out with warm water solution of mild liquid household detergent. (DO NOT USE PIPELINE SOAP OR OTHER POWDERS HAVING CAUSTIC COMPOUNDS IN THEM.)

11. If frequent filter change is encountered a large filter adapter kit is available (348-13 Models 350/500 and 353-13 Model 100). Also, the Peacekeepers for each model provide larger filters.

12. Relief Valves (348-17 and RV-463) are offered as optional equipment. They should be mounted between the pump and the vacuum controller. Relief Valves are factory set but should be reset on any given system because sizes of systems will vary. Settings can be adjusted to a higher vacuum by turning the screw clockwise and lower by turning the screw counter-clockwise. The adjustment screw is located in the center of the threaded end of the Relief Valves. Further instructions regarding placement and setting are available in an instruction sheet accompanying the valves.

Manuals here on the web are a work in process. We are adding pages so that eventually the complete manuals will reside here. Please check back, soon. Thank you!

To Buy Online go to our WebStore here ---->