Pressure gauges

The stainless steel pressure gauge is a product of high quality. The stainless steel pressure systems are all provided with seamless drawn tube which reduces the chance of tube rupture. All Pressure gauges have the connection welded into the case and is produced according to the international standard EN837 and the PED. The pressure gauges can be supplied with material certificates according EN10204 3.1, with NACE MR01-75 (ISO-15156) compliance and/ or calibration certificates. Our pressure gauges are also suitable to be supplied in explosive atmospheres and can be supplied with ATEX 114 compliance certification. The most safe stainless steel pressure gauge is the solid front type with baffle wall and blow out protection (BDT20).

Bourdon tube pressure gauges

Pressure gauges are among the most common and most used pressure measurement devices worldwide. The principle of the “Bourdon tube” was developed by Eugène Bourdon in 1849 but its technology is still being used. A bourdon tube pressure gauges consists of a bourdon tube bent into an arc or circle. the cross section of the tube is elliptical. One end of tube is connected to the connection where the pressure need to be measured, the other end is connected to a mechanism steering the pointer.

The working principle of a bourdon tube is that the when the process medium to be measured (gas or fluid) this flows in the tube and the elliptical cross section tends to become circular. This makes the tube to straighten itself with an increase in radius. this causes the free end of the tube to move or displace. This displacement steers the pointer via the mechanism and the pointer moves over the scale. Bourdon tubes are made in 2 different shapes, C-shape and a coil (or pigtail) shape type which has several winded coils of the same diameter (helical coils). The Pigtail is used for measuring high pressures starting above 60 bar and over.

Pressure gauges still are being used a lot in the heavy industries. They are fairly low cost and a simple and proven construction. They are available in a large variety of ranges. However, the instruments remain sensitive to shocks and vibrations. Pressure gauges remain essential in the industry though, because they don’t require any electricity and are easily remote readable and understandable. So in case of power shutdowns and local checks, the processes can still be checked and kept under control. Since pressure gauges are used more selectively, more attention is given to the right selection. In combination with diaphragm seals the durability and lifetime of the pressure gauges can be significantly prolonged ensuring longer uptime, less maintenance cost (less replacements in the field) lower procurement cost (fewer quantities because the no longer break) and increased safety for the operators.

Diaphragm pressure gauges

Badotherm has 2 type of diaphragm pressure gauges

For low pressure measurement, Badotherm type BDT12, it is a mechanical diaphragm construction. The diaphragm element is circular shaped, convoluted membranes that are welded between two flanges around the rim. The process pressure exerts a force on the diaphragm, a metal pushrod (link) fixed to the top of the diaphragm transmits the deflection of the diaphragm to the movement. The movement translates the lateral motion of the push rod into a rotational motion of the pointer.

Differential pressure gauges, Badotherm type BDT13, measures the difference between two pressures. This is down by means of a double diaphragm based on Badotherm diaphragm seal technology, measuring and exerting the pressure of both sides by means of it hydraulic system. These instruments are suitable for the monitoring of filter contamination, for level measurement in closed vessels, for overpressure measurement in clean rooms, for flow measurement of gaseous and liquid media and for the control of pumping plants. Badotherm BDT13 can be supplied in many exotic materials and can be equipped with diaphragm seals as well.

Capsule pressure gauges

Capsule element pressure gauges consist of two circular shaped corrugated membranes welded or soldered together at the outer sides. The pressure acts on the inside of the capsule and the expansion of the capsule creates a deflection of the capsule which is translated by a geared movement to a rotational movement causing the pointer to move over the face of the dial. This method is perfectly suitable to measure very low pressures from 16 up to 600 mbar. Depending on the type of capsule used it is possible to measure negative, compound or positive pressure. Capsule pressure gauges are made according to the EN 837 standard in the sizes 63mm, 100mm, and 160mm. Pressure gauges with capsule elements are suitable for gaseous media with low pressures.

Pressure gauge accessories

Badotherm has a wide range of pressure gauge accessories that can be supplied in combination with the pressure gauges. They can be supplied as loose items, but mostly them come complete assembled, pre-set and tested from the Badotherm factories. A short summary of the accessories are

Mounting brackets (BDT40)
Syphons (BDT42, BDT43, BDT44)
flanged process connections
Overpressure protectors (BDT49)
Adjustable snubbers and pulsation dampeners (BDT45, BDT46)
Swivel gauges adaptors (BDT47)
Extension nipples
Shut of valves and manifolds (BDTV910 or BDTM92x)

and of course, our diaphragm seals and related filling fluids