Esco Single-Piece Oil Sight Glass

Price From: $69.95

Quick Overview

Machined out of one solid piece of acrylic, this heavy-duty design eliminates any bonded parts that would wear out over time. With thicker walls and increased chemical compatibility, this robust Oil Sight Glass (OSG) is used in the harshest environments. These parts are designed to handle higher pressures as well as exposure to caustic chemicals that would potentially degrade O-rings or bonded parts in the other OSG designs. The Single-Piece premium OSG is the perfect product for the most aggressive applications. See below for product details, specifications, temperature and pressure ratings and part number chart.

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Price From: $69.95


Water wreaks havoc on lubrication systems, causing premature wear. With the Single-Piece OSG, users have immediate visual inspection of the oil and the ability to drain and accumulated water. The OSG is installed directly to a drain port located at the bottom of a reservoir or with an elbow for drain ports located on the sides of equipment. The spring-loaded drain valve is utilized to purge any accumulated water. Any sediment or particles in the lubrication fluid will matriculate to the OSG where, upon inspection, the user can determine appropriate action. The OSG is perfect on pumps, gearboxes, storage tanks or any fluid-lubricated machinery and built to withstand harsh environments.



  • Cast acrylic
  • Brass nipple
  • Brass drain valve

Recommended Temperature Range

  • -40° F to 200° F
  • -40° C to 93° C
  • Up to 200 psi

Available Options

  • 1 oz and 3 oz bottle sizes
  • ½” and ¾” NPT installation ports (adaptors available for other sizes)
  • Stainless steel hardware
  • Magnetic drain valve for ferrous particles

Choose A Size

Esco Single-Piece Oil Sight GlassDimensionsPart #
1oz, 1/4" NPT 1.75" OD, 3.5" L SPOSG1X250
1oz, 3/8" NPT 1.75" OD, 3.5" L SPOSG1X375
1oz, 1/2" NPT 1.75" OD, 3.5" L SPOSG1X500
1oz, 3/4" NPT 1.75" OD, 3.5" L SPOSG1X750
3oz, 1/4" NPT 2.25" OD, 4.25" L SPOSG3X250
3oz, 3/8" NPT 2.25" OD, 4.25" L SPOSG3X375
3oz, 1/2" NPT 2.25" OD, 4.25" L SPOSG3X500
3oz, 3/4" NPT 2.25" OD, 4.25" L SPOSG3X750