{"id":13512,"date":"2020-09-29T10:09:58","date_gmt":"2020-09-29T15:09:58","guid":{"rendered":"https:\/\/blog.wika.com\/us\/\/?p=13512"},"modified":"2025-09-22T12:35:40","modified_gmt":"2025-09-22T17:35:40","slug":"three-reasons-to-use-a-stainless-steel-pressure-gauge","status":"publish","type":"post","link":"https:\/\/blog.wika.com\/us\/products\/pressure-products\/three-reasons-to-use-a-stainless-steel-pressure-gauge\/","title":{"rendered":"Three Reasons to Use a Stainless Steel Pressure Gauge"},"content":{"rendered":"

Companies in the biotechnology, chemical, food processing, petrochemical, oil refining and other industries rely on gauges to keep their operations running properly. For engineers and technicians at these and other facilities, stainless steel pressure gauges serve critical roles for ensuring the safety and efficiency of various processes.<\/strong><\/p>\n

How do you choose a pressure instrument? The choice depends on numerous factors, mainly accuracy, features, utility, and safety. But how about the material: copper alloy (brass) or stainless steel? <\/p>\n

Brass is an economical and suitable option for many applications. However, for corrosion resistance, extreme temperatures, and overall system integrity, choose a stainless steel pressure gauge<\/a>.<\/p>\n

1. Protection against corrosion<\/h3>\n

Gauges with copper alloy (brass) wetted parts \u2013 socket, end piece, Bourdon tube, etc. \u2013 are excellent options for use around hydraulic oil, water, air, and other non-aggressive liquids and gases. However, only stainless steel resists the corrosion that can lead to system breaches and gauge failure. In general, use a stainless steel gauge around ammonia, creosote, aggressive solvents, or other harsh chemicals.<\/p>\n

But even with non-corrosive media, it is critical to verify the media compatibility and makeup of the copper alloy. This is because some media can be completely harmless in certain states and stages, yet become aggressive in the presence of other substances, such as water or oxygen. For example, carbon dioxide is chemically stable and inert, but becomes carbonic acid (H2<\/sub>CO3<\/sub>) when dissolved in water.<\/p>\n

2. Reliability in extreme temperatures<\/h3>\n

In very low ambient temperatures, such as found in the oil fields near the Arctic Circle, stainless steel pressure gauges are the better option. Why? To seal the socket and case together, most SS gauges have a welded connection rather than use an O-ring made of elastomer, which becomes brittle \u2013 and loses its sealing properties \u2013 at low temperatures. WIKA\u2019s PG23LT<\/a> stainless steel pressure gauge with silicone-oil case filling is especially designed for optimal performance in ambient temperatures down to \u221294\u00b0F (\u221270\u00b0C)<\/a>.<\/p>\n

In applications with very hot media, such as steam, stainless steel pressure gauges are the only viable choice. This is because brass gauges are soldered, and soldering has a much lower melting point than stainless steel. Use brass gauges when the media is below 140\u00b0F (60\u00b0C). Compare those to WIKA\u2019s XSEL\u00ae<\/sup> process gauges 232.34 and 233.34<\/a> with a welded stainless steel system, which has a short-term intermittent maximum temperature limit of 500\u00b0F (260\u00b0C).<\/p>\n

Note: An additional error of \u00b10.4% of span will occur for every \u00b118\u00b0F (10\u00b0C) deviation from the reference temperature of 68\u00b0F (20\u00b0C). As an example, an XSEL\u00ae<\/sup> process gauge is exposed to a media temperature of 158\u02daF. This is a difference of 90\u02daF from the reference temperature. Let\u2019s do the math:<\/p>\n

\u00a0 \u00a0 \u00a0 \u00a0 90\u00b0F \/ 18\u00b0F = 5
\n\u00a0 \u00a0 \u00a0 \u00a0 5 x 0.4% = 2.0%<\/p>\n

As the standard accuracy for an XSEL\u00ae<\/sup> is \u00b10.5%, the new total error for this pressure gauge becomes \u00b12.5% of full span when exposed to a media temperature of 158\u00b0F.<\/p>\n

3. System integrity<\/h3>\n

WIKA\u2019s \u201cAll Stainless Steel\u201d gauges models 23X.30<\/a>, 23X.50<\/a>, 23X.53<\/a>, and 23X.54<\/a> are laser welded between the socket and the case, which make them more durable in high-vibration applications. The typical O-ring seals in brass gauges are not very resistant to severe shocks and vibrations.<\/p>\n

Dry or Liquid-filled Case for a Pressure Gauge<\/h2>\n

Most WIKA\u2019s stainless steel pressure gauges come standard with either a dry liquid-fillable case or a liquid-filled case; both have an ingress protection<\/a> of IP65. We recommend that customers opt for liquid-filled gauges whenever possible because case filling:<\/p>\n