What is Accessory?
Accessory is an extra item added to something and is useful or attractive but is not essential. It is intended to support, supplement, and/or augment the performance of parent device.
What is Accessory for Pressure Gauges?
Accessory for Pressure Gauge is a device that is used with Pressure Gauge for specific / Specified application, to improve the Performance or Life of the Pressure Gauge.
Different Type of Accessory for Pressure Gauge
There are different types of accessories which can be used with pressure gauges depending upon the applications. For Pulsating fluid applications, Snubbers are used as an accessory, for applications where design pressure is more than the limit of pressure element, Gauge Saver is used as accessory, for Higher temperature applications we use Syphon, Impulse Tube or Cooling tower.
Syphon, Impulse Tube and cooling tower are having different designs and materials depending upon the various factors.
Gauge adaptors, Gauge unions are also used as an accessory for mounting matching different type of threads or for adjusting the position of the instrument.
Brief description of different accessories is as under:
SNUBBER
About Snubber
Snubber is a device used to suppress a phenomenon.
In pressure gauges, if this accessory is used, it suppresses the effect of Pulsation (i.e., Pressure Pulses or Pressure Peaks).
Snubber is also called as Pulsation Dampener.
Snubber is the device which is recommended with clear and clean liquids protects the pressure instruments from pressure pulsations / rapid pressure fluctuation. These are important accessory for instruments which undergo severe pressure pulsations like those located at the pump discharge. Pulsation is observed as the most common reason of pressure gauges failure.
These are made from Hex rod and normally divided in 3 Categories. Pressure up to 150 Bar, Pressure between 150 to 250 Bar and Pressure above 250 Bar.
Dia of Hex rod is increased for High pressure in other words thickness of wall is increased. These are available in 25mm, 28mm or 32mm Hex construction. Dimension wise Construction of different manufacturers may differ.
Material of Construction for Snubber
SS304, SS304L, SS316, SS316L, SS321, Monel, Other material can be provided as per customer’s requirement.
However, it depends on manufacturer to Confirm the Possibilities based on quantities applicable.
Based on quantities is mentioned because cost for small quantities will be much higher.
Process Connection for Snubber
½” NPT F x ½” NPT M, ¼” NPT F x ¼” NPT M, 3/8” NPT F x 3/8” NPT M, ¾” NPT F x ¾” NPT M, ½” BSP F x ½” BSP M, ¼” BSP F x ¼” BSP M, 3/8” BSP F x 3/8” BSP M, ¾” BSP F x ¾” BSP M.
BSP is normally written for BSPP type Threads, which are parallel threads. The connection of BSPT Types can also be provided if required by customer.
It can be provided with other combinations also like M x M or M x F or F x F. Other Types of Threads can also be provided like G, R or M Type.
Some Important points to be remembered:
We need to understand the basic difference between Pulsation and Vibration. Pulsation is a process phenomenon. For example, Pressure Pulses & Pressure Peaks at discharge of the pump are pulsations, however, Vibration is a mechanical phenomenon and example of the same is movement of the body of the Pump.
If we are having pulsation in process, the best accessory is Snubber and if we have mechanical vibration, snubber will not be suitable. We need to opt for Liquid Filled Casing.
Liquid for filling can be selected based on ambient Temperature Conditions. Different fluids are used for specific applications. Customers are not always accepting glycerin, Silicon etc.