"What is the minimum and maximum temperature limit?"
The materials of construction of the unit determine temperature limitations. Operating temperatures can be -40°F (-40°C) to over 400°F (205°C). When consulting the material specifications for temperature ranges, be sure to check the bladder material and the wetted and non-wetted housing material. If you are unsure of the proper component materials, or you need assistance, please Contact Us.
CAUTION: All materials lose strength as temperature rises.
"How do I size a dampener, suppressor or stabilizer?"
Proper sizing is based upon several variables. The Blacoh sizing formulas allow you to input the specifics of your application to calculate the proper size. You can contact your local distributor or Blacoh for any sizing and application assistance you require. You can also request a CD with complete sizing formulas.
"What is the difference between the Automatic, Adjustable, Chargeable and Stabilizer air controls on SENTRY units?"
Different air controls are used for different types of applications. The next four questions explain each control type.
"How does the chargeable air control work?"
The Chargeable model has a Schrader type charging valve that allows for a predetermined pressure charge to be applied and held in the dampener. No permanent source of compressed gas is required to be attached to the unit. The Chargeable models are used primarily with metering, piston and peristaltic pumps for pulsation dampening. Chargeable models are also used for surge suppression to prevent water hammer from quick closing valves, for make-up fluid to prevent pump cycling and for suppression of pump start up or shutdown pressure spikes.
"How does the adjustable air control work?"
The Adjustable model uses a self-relieving regulator to set dampener pressure. A compressed air line must be permanently attached to the regulator. The regulator allows for an easy, convenient method for readjusting the dampener if the system fluid pressure changes. Adjustable units are designed for use on air operated diaphragm pumps in systems with a constant discharge pressure.
"How does the automatic air control work?"
An automatic poppet type valve located in the non-wetted section of the dampener allows for an increase in compressed air pressure to balance an increase in system liquid pressure. As liquid system pressure increases, the bladder is pushed further up into the dampener until it touches the internal automatic valve. This contact opens the valve and allows an increase of compressed air to enter the dampener. When the air pressure equals the system liquid pressure, the dampener is in balance and pulsations are minimized. If a change in pressure occurs this process is repeated. Automatic units are designed for use on air operated diaphragm pumps in systems with a varying discharge pressure.
"How does the inlet stabilizer air control work?"
The Inlet Stabilizer air control consists of a compound pressure gauge, a pressure/vacuum tight ball valve and a venturi valve. When compressed air is passed through the venturi valve at high speed, a low pressure area is created which is used to evacuate the air from the stabilizer, creating a vacuum internally. Conversely, when the flow of air through the venturi valve is diverted into the stabilizer, a pressure charge is obtained. When pump inlet conditions are optimized, pump efficiency is maximized.
"What compressed gas do I use to charge the unit?"
Use compressed air or nitrogen for units up to a maximum pressure rating of 150 PSI (10 BAR). Use nitrogen for all units with a maximum pressure over 150 PSI.
CAUTION: Never Use Oxygen
"To what pressure should the dampener, suppressor or stabilizer be charged?"
Dampeners are charged to 80% of the liquid flowing pressure. Surge suppressors (water hammer control) are charged to 95% of flowing pressure. Inlet stabilizers are charged to 50% of positive static inlet pressure or to 5 of vacuum for suction lift conditions. See the operating instructions for more detail.
"Where should the dampener, suppressor or stabilizer be installed?"
Within 10 pipe diameters of the source of the pressure fluctuation; i.e. at the pump discharge for pulsation, at the pump inlet for inlet stabilization, upstream of a quick closing valve for water hammer, and at the discharge of a centrifugal pump for start up and/or shutdown.
"How is the SENTRY unit mounted?"
Since pressure is equal in all directions, SENTRY can be installed in a vertical, horizontal, or upside-down position. Blacoh recommends a vertical installation for better draining of the unit. Limitations for horizontal and upside-down mounting include high specific gravity, high viscosity, settling of solid material, or possible air entrapment, which could result in shortened bladder life and/or reduced dampening.
"What direction is the bladder installed?"
Rubber bladders are always installed with the open end away from the dampener inlet, whether in dome or flat top models. The PTFE Bellow is installed with the open end of the bellows facing up in flat top models. PTFE bellows in dome top models are assembled with the open end of the bellows facing down.
"How can I tell if my dampener is working properly?"
If the dampener is sized and installed correctly, pump pulsations should be reduced to a very minimal amount. If a pressure gauge is installed at the pump discharge, the gauge pressure reading should usually only vary by 3 to 10 PSI (.207 to .689 BAR). Inlet stabilizers work the same way on the inlet side of the pump. Please consult Blacoh or your local distributor if the dampener does not appear to be working properly or if the residual pulsation is greater than expected.
"Why is the gauge not reading 0 PSI when the pump is off and the dampener is depressurized?"
The gauge has probably been damaged by momentary system over-pressurization. Check for a quick closing valve in the system which when closed can cause a pressure spike in excess of the maximum gauge pressure rating. CAUTION: Make sure all pressure is released from the dampener before disassembly of the unit.
"Why does my dampener lose pressure?"
The primary reason a dampener will not hold pressure is a failed bladder. The dampener should be inspected and the bladder replaced if it has failed. A soapy spray should be used to check the fittings around the control package at the top of the dampener as vibration over time can loosen these fittings. For a complete unit test, the dampener should be removed from the system. Charge the unit to working pressure and submerge under water. Any leakage will be seen as air bubbles. CAUTION: Make sure all pressure is released from the dampener before disassembly of the unit.
"Can I use a SENTRY to dampen airflow?"
Generally Blacoh dampeners are used to minimize hydraulic pressure/flow fluctuations. There are some applications where a Blacoh dampener has been successfully used to dampen pneumatic pulses. Please Contact Us for an analysis of your application.
"Can I use a plastic model in a "water hammer" or "surge" application?"
Water hammer is usually caused by a quick closing valve located somewhere in a liquid piping system. When a valve closes quickly, a pressure spike above 150 PSI is usually created. Plastic dampener models can only be used for pressure up to 150 PSI (10 BAR) at ambient temperature. For "water hammer" or surge, a metal model with a higher pressure rating must be used.
"What should I torque the bolts to on Blacoh products?"
Each Blacoh model has its own fastener torque specifications. Please Contact Us for assistance.
"What is the material Aflas that you offer in bladders?"
Aflas is basically a Viton rubber filled with 20% PTFE. It is primarily for strong acids and/or high temperature applications up to 400º F (204º C).
"Can I order special inlet connections?"
Blacoh can custom tailor almost any type of dampener or stabilizer inlet connection. We offer NPT and BSP threads, ANSI and DIN flanges, tri-clamp fittings, butt weld ends, metric flare type fittings, and many more. Please contact Blacoh for your specific needs.
"Are material and pressure test certificates available?"
Yes. Blacoh maintains traceability of most materials used in our dampeners. Additionally, every dampener manufactured is tested prior to shipping, and a pressure test certificate can be provided upon request. Any material and/or pressure certification must be requested at the time of order.
"Does Blacoh have a "3A" designated dampener?"
3A has recently approved a pulsation dampener and Blacoh will be submitting a design for acceptance in the near future. Please consult Blacoh for the latest status on ?3A? designation for your required model(s).
"Do SENTRY units have ASME coding on the pulsation dampeners?"
No. ASME (American Society of Mechanical Engineers) standards do not apply until the internal diameter of the dampener exceeds 6 inches. Blacoh models up to 370 cubic inch (6L) sizes are under this dimension. All Blacoh dampeners have a burst pressure three or more times higher than the maximum operating pressure specified. For specific ASME information on other sizes, please Contact Us.
"Do SENTRY units have the Canadian CRN designations?"
Blacoh dampeners currently do not have the Canadian CRN designation. Most Blacoh models are exempt from this requirement and it is seldom requested. If required, we can apply for the CRN designation for certain models. Please Contact Us for more specific Information.
"Do Blacoh products meet the new European ATEX safety standards?"
Many Blacoh models and sizes have ATEX certification with new models and sizes added on a daily basis. Please Contact Us for the latest status on ATEX certification for your required model(s).
"Do Blacoh dampeners and suppressors comply with the European Pressure Directive?"
Blacoh dampeners and suppressors comply under Sound Engineering Practices (SEP) and Simple Pressure Vessel codes. In some cases, however, compliance requires a lowered pressure rating. Please Contact Us for information specific to your required model(s).
"Where can I purchase Blacoh products?"
Blacoh sells its products through a worldwide network of authorized distributors and select OEM customers. Our distributors provide our end users with any local assistance they require. Please Contact Us.
"What is the lead time for delivery?"
Lead time for shipment of Blacoh products is normally 24 to 48 hours for standard items.
"What is Blacoh?s warranty policy?"
All Blacoh products, with the exception of Sentinel Diaphragm Seals and PTFE bellows, are guaranteed for workmanship and material for 2 years from shipment. Sentinel Diaphragm Seals and PTFE bellows carry a three year guarantee of performance. There are certain limitations and restrictions. Contact Us for complete details.
"What sizes are available?"