Reagent Head Assembly
The typical reagent head assembly consists of reagent head, diaphragm, and suction and discharge cartridge check valves. This assembly is the only part of the pump to contact the process liquid; consequently, maintenance is critical to pump performance.
Control Assembly
The BLACKLINE® pump incorporates a lost motion style of stroke length adjustment to limit diaphragm travel during the suction portion of each stroke. The stroke length setting is indicated by a (0% – 100%) scale located on the stroke adjustment assembly.
Stroke length is changed by turning the hand knob. This turns a mechanism, which limits rearward travel of the diaphragm. Refer to Section 6.4 for further information.
For automatic flow rate control, users can consider the Pulsafeeder VFD speed based control system, please contact your local Pulsafeeder dealer or representative for more information.
Gear Ratio Assembly
BLACKLINE® pumps are driven by an electric motor mounted on the motor adaptor input flange. The motor drives a set of worm gears that convert rotational speed into torque. They, in turn, power the eccentric shaft assembly that converts rotary motion into reciprocating motion.
Equipment Inspection
Check all equipment for completeness against the order and for any evidence of shipping damage. Shortages or damage must be reported immediately to the carrier and your authorized representative or distributor of BLACKLINE® pumps.
Storage
Short Term
Storage of your BLACKLINE® pump for up to 12 months is considered short-term. The recommended short-term storage procedures are:
- Store the pump indoors at room temperature in a dry environment.
- If required by the operating environment, take precautions to prevent entry of water or humid air into the eccentric enclosure.
- Prior to startup, perform a complete inspection and then start up in accordance with instructions in this manual.
Long Term
Every twelve months, in addition to the above short-term procedures, verify the oil level, power up the motor and operate the pump for a minimum of one hour. It is not necessary to have liquid in the reagent head during this operation, but the suction and discharge ports must be open to atmosphere.
After twelve months of storage, Pulsafeeder’s warranty cannot cover items that are subject to deterioration with age, such as seals, gaskets, and diaphragms. If the pump has been in storage longer than 12 months it is recommended that these items be inspected and replaced as necessary prior to startup. Materials and labor to replace this class of item under this circumstance are the purchaser’s responsibility. Consult your local Pulsafeeder representative for assistance in obtaining parts and service for your pump.
Installation
PUMP IS NOT TO BE USED TO HANDLE OR METER FLAMMABLE LIQUIDS OR MATERIALS!
Location
When selecting an installation site or designing a chemical feed system, consideration should be given to access for routine maintenance.
BLACKLINE® pumps are designed to operate indoors and outdoors, but it is desirable to provide a hood or covering for outdoor service. External heating is required if ambient temperatures below 0 C (32 F) are anticipated, especially if pumps are not in continuous duty. Check with the factory if concerned with the suitability of the operating environment.
The pump must be rigidly bolted to a solid and flat foundation to minimize vibration, which can loosen connections. When the pump is bolted down, care must be taken to avoid distorting the base and affecting alignments. The pump must be level within 5. This will assure that the check valves can operate properly.
Piping System
- All systems should include a pressure relief valve on the discharge side, to protect piping and process equipment, including the pump, from excess process pressures. An external relief valve is required! There should be no devices capable of restricting flow (such as a valve) located between the pump and the relief device.
- Shutoff valves and unions (or flanges) on suction and discharge piping are recommended. This permits check valve inspection without draining long runs of piping, making periodic maintenance and inspection easier. Shutoff valves should be of the same size as connecting pipe. Ball valves are preferred since they offer minimum flow restriction.
- Suction systems should include an inlet strainer, if appropriate for the product being pumped. Pump check valves are susceptible to dirt and other solid contaminants, and any accumulation can cause malfunction. The strainer should be located between the suction shutoff valve and the pump suction valve. It must be sized to accommodate the flow rate and the anticipated level of contamination. A 100 mesh screen size is generally recommended for up to 4 GPH, 60 Mesh for up to 13 GPH, 50 mesh for up to 26 GPH, 40 Mesh for up to 79 GPH and 30 mesh for flow rates above 80 GPH.
- Vacuum/pressure gauges in the suction and discharge lines are helpful in order to check system operation. Gauges should be fitted with protective shutoff valves for isolation while not in use.
- Piping weight must not be supported by valve housings or other portions of the reagent head, as the resulting stresses can cause leaks. If appropriate, provide for thermal expansion and contraction so that no excess force or moments are applied to the pump.
- When making process connections, ensure that the check valve assemblies do not rotate as the threaded connections are secured. It is critical, especially with plastic construction, that the check valves not be too tight into the reagent head. The threaded connection between the check valve assembly and the regent head uses an o-ring seal and does not require sealing tape or any other sealant.
- In piping assembly, use a sealing compound chemically compatible with the process material. Users of sealing tape are cautioned to ensure that the entering pipe thread ends are not taped, and that tape is removed from previously-used threads to the maximum practical extent prior to re-use. Both new and existing piping should be cleaned, preferably by flushing with a clean liquid (compatible with process material) and blown out with air, prior to connection to the pump. Debris from the piping system that prevents proper check valve operation is a common startup issue.
- Note that for pumps which utilize cartridge-type check valve assemblies, no thread tape or sealant is required on the threads which secure the cartridge assembly to the pump reagent head. This area is sealed with o-rings integral to the cartridge. Sealant on these threads can actually degrade sealing capability.
- For processes that require continuous non pulsating flow a pulsation dampener must be installed in the discharge line.
Although BLACKLINE® metering pumps have some suction lift capability, a flooded suction (i.e., suction pressure higher than atmospheric pressure) is preferable whenever possible. The pump should be located as close as possible to the suction side reservoir or fluid supply source.
For fluid with a vapor pressure of 5 psia or less (at operating temperature) the wet suction lift capability is approximately five (5) feet. If this requirement is not met, the pump will not provide reliable, accurate flow. In suction lift conditions, the use of a foot valve is recommended at the lowest point of the pickup tube or pipe. Pumps under suction lift conditions may require some liquid priming before they will operate reliably.
All BLACKLINE® metering pumps are designed for continuous service at the rated discharge pressure. If system suction pressure exceeds discharge pressure (a condition sometimes described as “pumping downhill”), flow would be generated (siphoning) in addition to that caused by the pump. This results in a reduction in accuracy and loss of control over the metering process. To prevent this flow-through condition, the discharge pressure must exceed suction pressure by at least 0.35 Bar (5 psi). This can be achieved where necessary by the installation of a backpressure valve in the discharge line. Conditions where the actual discharge pressure exceeds the pump’s rating are to be avoided as they will cause damage to the pump components.
