{"product_id":"castair-guard-louver-25x14x30-black-gl251430b","title":"Castair Guard\/Louver 25x14x30 Black - *GL251430B","description":"\u003ch2\u003eCastair Liquid-Filled Pressure Gauge — 1\/4\" NPT, 2.5\" Dial, 0-300 PSI, Back Mount (*GL251430B)\u003c\/h2\u003e\n\u003cp\u003eThe *GL251430B is a liquid-filled 2.5-inch pressure gauge with a 1\/4\" NPT back-mount connection and a 0-300 PSI range. This is the gauge Castair uses on their own compressors where vibration, pulsation, or shock loading would cause a dry gauge to bounce and wear out the bourdon tube and movement prematurely. The liquid fill — typically glycerin — dampens needle movement, protects the internal mechanism, and lets you read the gauge accurately under running conditions. If you need to replace a gauge on a Castair compressor and the original was liquid-filled, this is the correct replacement.\u003c\/p\u003e\n\n\u003ch2\u003eWhy Liquid-Filled vs. Dry Gauge?\u003c\/h2\u003e\n\u003cp\u003eOn a running piston compressor, pressure pulses with every stroke. A dry gauge needle bounces with each pulse, which makes it hard to read and wears the pointer pivot and gear mechanism quickly. A liquid-filled gauge damps those pulses — the needle holds steady, you can read it at a glance, and the mechanism lasts years longer. Liquid-filled gauges also handle external vibration better, which matters on compressors mounted on rolling carts or vibrating floors.\u003c\/p\u003e\n\u003cp\u003eThe tradeoff: liquid-filled gauges cost slightly more, and if the casing cracks, the glycerin leaks. But on a compressor application with real pulsation, liquid-fill is the correct choice.\u003c\/p\u003e\n\n\u003ch3\u003eGauge Specifications\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eFill:\u003c\/strong\u003e Liquid-filled (glycerin) — dampens vibration and pressure pulses for stable needle reading\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eConnection:\u003c\/strong\u003e 1\/4\" NPT — standard for piston and rotary compressor pressure ports\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMount:\u003c\/strong\u003e Back mount — pipe enters from the back of the gauge, face reads forward. Use when the gauge mounts to a panel, manifold, or tank fitting with the face pointing outward.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDial Size:\u003c\/strong\u003e 2.5 inches — readable from several feet away\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRange:\u003c\/strong\u003e 0-300 PSI — covers all Castair piston compressor operating pressures (95-175 PSI cut-out range) with substantial headroom\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFrame:\u003c\/strong\u003e Steel frame construction — durable for industrial shop environments\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePart Number:\u003c\/strong\u003e *GL251430B\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eCastair Gauge Lineup — Finding the Right Gauge for Your Application\u003c\/h2\u003e\n\u003cp\u003eCastair offers a full range of gauges. The model number encodes the specs:\u003c\/p\u003e\n\n\u003ch3\u003eDry Gauges — Steel Frame\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eG151860B\u003c\/strong\u003e — 1\/8\" NPT, 1.5\" dial, 0-60 PSI, back mount\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eG151860U\u003c\/strong\u003e — 1\/8\" NPT, 1.5\" dial, 0-60 PSI, bottom mount\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eG151816B\u003c\/strong\u003e — 1\/8\" NPT, 1.5\" dial, 0-160 PSI, back mount\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eG151816U\u003c\/strong\u003e — 1\/8\" NPT, 1.5\" dial, 0-160 PSI, bottom mount\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eG201420B\u003c\/strong\u003e — 1\/4\" NPT, 2\" dial, 0-200 PSI, back mount\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eG201420U\u003c\/strong\u003e — 1\/4\" NPT, 2\" dial, 0-200 PSI, bottom mount\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eG251430B\u003c\/strong\u003e — 1\/4\" NPT, 2.5\" dial, 0-300 PSI, back mount\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eG251430U\u003c\/strong\u003e — 1\/4\" NPT, 2.5\" dial, 0-300 PSI, bottom mount\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eLiquid-Filled Gauges — Steel Frame\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e*GL251430B — THIS PRODUCT\u003c\/strong\u003e — 1\/4\" NPT, 2.5\" liquid-filled, 0-300 PSI, back mount\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e*GL251430U\u003c\/strong\u003e — 1\/4\" NPT, 2.5\" liquid-filled, 0-300 PSI, bottom mount\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eFlanged Dial Gauge\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eGF251430B\u003c\/strong\u003e — 1\/4\" NPT, 2.5\" flanged dial, 0-300 PSI, bottom mount\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eBack Mount vs. Bottom Mount — Which Do You Need?\u003c\/h2\u003e\n\u003cp\u003eBack mount (*GL251430B): The pipe fitting is on the back of the gauge body. The gauge mounts flat against a panel or manifold, face pointing toward the viewer. Use this when the gauge is mounting to a panel or tank port and you want a clean flush-mount look.\u003c\/p\u003e\n\u003cp\u003eBottom mount (*GL251430U): The pipe fitting is on the bottom of the gauge body. The gauge hangs or protrudes from a horizontal pipe or fitting, face pointing upward or outward. Use this for in-line pipe installations or when the fitting is below the gauge.\u003c\/p\u003e\n\u003cp\u003eIf you are replacing an existing gauge, note which direction the pipe enters — that tells you whether you need back or bottom mount.\u003c\/p\u003e\n\n\u003ch2\u003eWhat's in the Box\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e1 x Castair liquid-filled steel frame pressure gauge (*GL251430B)\u003c\/li\u003e\n\u003cli\u003e1\/4\" NPT back-mount connection (male threads)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eTechnical Specifications\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003ePart Number:\u003c\/strong\u003e *GL251430B\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eConnection Size:\u003c\/strong\u003e 1\/4\" NPT\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMount:\u003c\/strong\u003e Back mount\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDial Size:\u003c\/strong\u003e 2.5 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePressure Range:\u003c\/strong\u003e 0-300 PSI\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFill:\u003c\/strong\u003e Liquid-filled\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFrame:\u003c\/strong\u003e Steel\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eApplication:\u003c\/strong\u003e Castair piston and rotary screw compressors, air receivers, pressure manifolds\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhy Buy From Air Compressor Factory Direct?\u003c\/h3\u003e\n\u003cp\u003eWe have supplied genuine Castair compressor parts and accessories since 2016. When you need to replace a gauge on a Castair unit, getting the factory part ensures the correct range, mount type, and dial size — a mismatched gauge is either unreadable or creates a fitting problem. We carry the full Castair gauge lineup and can help you confirm the right part for your compressor. Free shipping, free tech support at 866-217-0063, and the full Castair warranty.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eCall 866-217-0063 for quick answers and help!\u003c\/strong\u003e\u003c\/p\u003e","brand":"Cast Air","offers":[{"title":"Default Title","offer_id":53342498717909,"sku":"*GL251430B","price":41.18,"currency_code":"USD","in_stock":true}],"url":"https:\/\/aircompressorfactorydirect.com\/products\/castair-guard-louver-25x14x30-black-gl251430b","provider":"Air Compressor Factory Direct","version":"1.0","type":"link"}