A dampening device is used when a pressure instrument may be exposed to repetitive pressure fluctuations that are fairly rapid, high in magnitude and especially when transitory pressure spikes are present that exceed the instrument range. Throttle screws and plugs - provide dampening at an economical cost. They have the benefit of fitting completely within the gauge socket and are available in three types 1. A threaded type which permits easy removal for cleaning and replacement: 2. A Pressed in, non-threaded design and 3. A Pressed in, threaded design which provides a highly restrictive, helical flow path. Not all styles are available on all pressure instrument types. Pulsation Dampener/AshcroftÂ® model 1106 - threads onto an instrument socket and provides restriction by means of moving a pin, which may be placed in either of five different sized holes and thus allows the user to vary the amount of dampening to suit requirements. The pulsating pressure moves the pin up and down, providing a self cleaning action. Pressure snubber/AshcroftÂ® model 1112 - used for dampening and filtering, the snubber has a metal disc available in four standard grades of porosity 1. D: for use with oil, 2. E: for use with water and light oils, 3. G: for use with air, steam, and gases, 4. HX: for use with mercury. Due to the large filter area, the snubber has fewer tendencies to clog than orifice type devices. Needle Valves/AshcroftÂ® models 7001/7004 - an adjustable throttling device for severe applications. It provides the most practical means for varying the orifice to determine the exact orifice for any specific service condition. Pressure Limiting Valve - protects pressure instruments against surges and pulsations. Provides automatic positive pressure protection and accurate repeatable performance. Automatic pressure shut-off. Built in snubber enhances instrument, protecting performance.
Ashcroft provides a standard certificate of conformance with each packing list, we also offer a signed certificate of conformance with added statements when requested by you, the customer. To order a signed certificate of conformance - please be sure you include the CD1A option with your part number.
A certified calibration certificate provides the user with a serial numbered instrument along with a calibration certificate that it has been calibrated/certified in accordance to the pressure instrument standards with instruments that are traceable to NIST. A certified calibration chart made per: ASME B40.100 2013 Pressure gauges & attachments. ASME B40.200 2008 Thermometers with masters traceable to NIST To order a certified calibration certificate - please make sure you have the XC4 option in your part number.
ISO/IEC 17025 accreditation is the single most important standard for calibration and testing laboratories around the world. ISO 17025 accredited laboratories have demonstrated that they are technically proficient and able to produce precise and accurate test and calibration data. This is a voluntary, third party-reviewed process that ensures a laboratoryâs quality management system and is thoroughly evaluated on a regular basis to guarantee continued technical competence and compliance with ISO 17025.
Laboratory accreditation bodies use the ISO 17025 standard specifically to assess factors relevant to a laboratoryâs ability to produce precise, accurate test and calibration data, including:
- Traceability of measurements and calibrations to national standards
- Technical competence of staff
- Maintenance of test equipment
- Quality assurance of test and calibration data
- Validity and appropriateness of test methods
- Appropriate handling and transportation of test items
- Quality of testing environment and sampling
To ensure continued compliance, accredited laboratories are regularly re-assessed to check that they are maintaining their standard of technical expertise. These laboratories are also required to participate in regular proficiency testing programs as an ongoing demonstration of their competence.
ISO/IEC 17025 accreditation helps to minimize risk by ensuring that you are choosing a technically competent lab that has a sound quality system in place. This also allows you to avoid expensive retesting, which enhances your confidence in our product by assuring that it has been thoroughly evaluated by a competent testing calibration laboratory that has been assessed by a third party.
A diaphragm seal is an isolation device that is attached to the inlet connection of a pressure instrument to isolate its measuring element from the process media. A diaphragm seal is commonly used in a variety of process applications where corrosives, slurries or viscous fluids may be encountered. The diaphragm seal affords protection to the instrument where: The process fluid being measured may clog the pressure element. Pressure element materials capable of withstanding corrosive effects of certain fluids are not available. The process fluid may freeze due to changes in ambient temperature and cause damage to the element.
What AshcroftÂ® instruments are not available with diaphragm seals?
The 2174 is powered by the 4-20mA signal, while the 2274 is powered using a separate power supply. If the model 2274 includes the optional 4-20mA output or switch(s) the output signal and switches will have separate contacts from the power supply.
My digital gauge is flashing, won't zero and may/may not be reading pressure. (OVER, UNDER, O/P, U/P)
By re-scaling the graph, the 4-20mA can also be re-scaled. Accuracy of the gauge is based on full scale range. Re-scaling the graph does not change the full scale range. Instructions to alter the graph are in the Installation and Maintenance manual - see page 12.
Do you sell digital gauge field replacement parts?
Pressure pulsation can be dampened by several mechanisms; our patented PLUS!â¢ Performance gauge will handle the vast majority of applications. One exception to this is high frequency pulsation which is difficult to detect. The only indication may be an upscale zero shift due to movement wear. These applications should be addressed with a liquid filled gauge, or in extreme cases, a remotely mounted liquid filled gauge connected with a line of capillary. The small diameter of the capillary provides excellent dampening, but can get plugged. Pulsation dampeners and snubbers are alternative auxiliary devises which dampen pulsation with fewer tendencies to plug. Also throttle plugs or throttle screws inserted in the pressure connection of the pressure gauge may help solve this problem.
This is quite subjective and depends upon the severity of the indicated pressure. The environmental limitations for the pressure gauge series should be observed in all cases. Gauges used in situations outside these requirements may result in inaccuracies, premature wear and/or failure of the gauge and would require additional maintenance. The frequency of calibration therefore, is best left to the user to determine.
The range of the instrument should be approximately twice the maximum operating pressure. Too low a range may result in low life due to fatigue of the elastic element due to high operating stress and susceptibility to overpressure set due to pressure transients that exceed the normal operating pressure. Too high a range may yield insufficient resolution for the application.
Ashcroft offers many different types of pressure connections based on different products. Please consult the data sheets, if you do not see the connection you require please contact us at firstname.lastname@example.org or by calling our ActionLineÂ® at 1-800-328-8258
A 3-2-3% of span designation stands for 3% in the first quarter of the scale, 2% in the middle half of the scale, and 3% in the last quarter of the scale. This accuracy is typically associated with commercial grade pressure gauges. (visual)
What types of accuracy does Ashcroft offer for pressure gauges?
Proof pressure is the maximum pressure a gauge can withstand without evidence of change in accuracy. Burst pressure is the maximum pressure above which the pressure assembly may no longer hold pressure. Please refer to product information page ASH/PI-42C
The setpoint is the pressure, temperature, or differential pressure value where the electrical switch makes or breaks contact. The unit will return to the original or normal position once the switch reset point has been achieved.
Static pressure is the pressure exerted by a fluid or gas that is not moving or flowing. For differential pressure applications the static pressure refers to the lower of the two pressures applied to the actuator
A term commonly used in the industry referring to enclosures capable of withstanding an internal explosion of a specified gas without igniting surrounding gases. Strict installation practices in accordance with the national electrical code are also required for safety. Ashcroft currently offers many different types of explosion proof approvals such as UL, FM, CSA, ATEX, and IECEx.
Can AshcroftÂ® switches be cleaned for Gaseous Oxygen Service?
Accuracy normally refers to conformity of an indicated value to an accepted standard value. Since there is no indication in switch products, the term repeatability is used as the key performance measure. Repeatability is the closeness of agreement among a number of consecutive measurements of the output setpoint for the same value of the input under the same operating conditions, approaching from the same direction for full range traverses. Using this definition, the accuracy and repeatability of an AshcroftÂ® pressure switch is typically +/- 1% of full range.
What is the difference between proof and burst pressure?
Proof pressure is the maximum pressure which can be applied to a pressure switch without causing damage. While burst pressure is the maximum pressure that can be applied to a switch without causing leakage or rupture. A switch that has been subject to proof pressure should still be operational, but may require a recalibration of the setpoint. However, a switch that has been subject to the pressures near or at the burst pressure can be permanently damaged.
What is deadband (Hysteresis) in regards to a pressure switch?
No, but in the A, B, F, G, L, and P series you can get a unit that has 2 SPDT switches that actuate at the same setpoint to simulate a DPDT switch. SPDT - Form C contact - single pole double throw, one contact which flips over, switching the input from Normally Closed to Normally Open. DPDT - 2 Form C contacts - double pole double throw, the same but two ganged together.
A Thermowell performs an invaluable triple-duty service: 1.) it protects delicate instrument sensing elements against corrosive effects and physical damage caused by media flow, 2.) it permits the instrument interchange or calibration check without disturbing or closing down the process and 3.) it helps to contain costly or dangerous process fluids when properly installed as an integral part of the vessel or piping.
What cable lengths are available for the electric contacts?
For most model pressure transducers, Ashcroft offers mating connectors and cable harnesses. Please contact the factory with the model/part number of your transducer so we advise a connector/harness part # and an Ashcroft dealer to purchase from.
Do the GC30 or GC31 products replace any current AshcroftÂ® products?
Ashcroft manufacturing has standardized on 4 conductor cables, so one or two wires may not be used. Please install per the instructions in the Installation and Maintenance manual, using on the appropriate wires.
The transducer is labeled as Ashcroft, but I cannot locate the model number printed on the label on either the Ashcroft website or through an internet search?
The model transducer you are searching might have been discontinued and replaced by a new model, or it could be a custom model number normally sold to OEM's and not listed on the Ashcroft website. Please contact Ashcroft with the model number, information printed on the label and a picture of the unit if possible.
How frequently should an AshcroftÂ® transducer be recalibrated?
1. Confirm the wiring is correct, Installation and Maintenance manuals are helpful here. 2. Confirm the power source is good and appropriately sized. Units require the necessary power at the transducer, not at the source. 3. Check with an external meter for expected output. If all issues are checked and the problem cannot be resolved, we ask that you contact an Ashcroft product specialist.
Do you offer anything that could read/display the pressure of the transducer?
The model transducer needed is normally determined by the specifications required which include: pressure range, output, process connection, electrical connection, media compatibility, and accuracy. Other factors include specific agency approvals such as CE, Intrinsically Safe or Hazardous Duty. Ingress Protection ratings and quantity of transducers can also help identify which AshcroftÂ® model to select.