What Are DES-CASE VentGuard Breathers and How Do They Work?
DES-CASE VentGuard Series breathers use check-valve technology to isolate the system and only allow airflow — or ‘breathing’ — when pressure differential demands it. The check valve cracks at just 0.1 psi (0.007 bar), meaning the desiccant media is not exposed to humid ambient air during idle periods. This makes VentGuard an ideal solution for low-to-medium flow applications with intermittent operations, such as gearboxes, pumps, hydraulic reservoirs, and bulk storage tanks.
All five models — DC-VG-BB, DC-VG-1, DC-VG-2, DC-VG-3, and DC-VG-4 — share a common 3 μm absolute filter efficiency and an operating temperature range of -20°F to 200°F (-29°C to 93°C). Color-indicating silica gel desiccant turns from blue to pink as it saturates, providing a visible service indicator without instrumentation.
What Sizes and Desiccant Capacities Does the VentGuard Series Offer?
The VentGuard line spans two physical styles — Miniature and Standard — covering a wide range of reservoir volumes. Desiccant charge ranges from 0.1 lbs (59 g) in the DC-VG-BB up to 2.0 lbs (913 g) in the DC-VG-4, with corresponding maximum water adsorption capacity from 0.8 fl oz (23 ml) to 12 fl oz (356 ml).
- DC-VG-BB (Miniature): 0.1 lbs desiccant, 0.8 fl oz water capacity, suits gearboxes/tanks up to 15 gal (57 L)
- DC-VG-1 (Miniature): 0.3 lbs desiccant, 1.7 fl oz water capacity, suits gearboxes/tanks up to 35 gal (132 L)
- DC-VG-2 (Standard): 0.8 lbs desiccant, 5 fl oz water capacity, suits gearboxes/tanks up to 200 gal (757 L)
- DC-VG-3 (Standard): 1.4 lbs desiccant, 9 fl oz water capacity, suits gearboxes/tanks up to 350 gal (1325 L)
- DC-VG-4 (Standard): 2.0 lbs desiccant, 12 fl oz water capacity, suits gearboxes/tanks up to 500 gal (1893 L)
How Do You Size a VentGuard Breather for Your Reservoir?
Sizing is based on two primary application categories: Gearbox, Pump & Storage Tank versus Hydraulic & Central Lube Reservoir. Hydraulic systems experience higher fluid displacement per unit volume and therefore require a larger breather relative to reservoir size than gearbox or storage applications.
For hydraulic and central lube reservoirs, the DC-VG-BB handles up to 2 gal (8 L) while the DC-VG-4 handles up to 200 gal (757 L). For gearboxes, pumps, and storage tanks, those same two models cover up to 15 gal (57 L) and 500 gal (1893 L), respectively. Maximum airflow at 1 psi differential pressure ranges from 1 cfm (41 l/min) for both miniature models up to 12 cfm (340 l/min) for the DC-VG-2.
Des-Case notes that humidity level, frequency of airflow, ambient temperatures, and chemical compatibility must all be factored in. Larger applications and special circumstances require more thorough analysis; contact Des-Case technical support for assistance.
What Are the Thread Options and Dimensions for VentGuard Models?
Miniature models (DC-VG-BB and DC-VG-1) use a 3/8
Step-by-step
Multi-Fit Male Thread with O-Ring Seal, compatible with 3/8
Products discussed in this episode
- Des-Case DC-VG-1 Desiccant Breather
- DES-CASE Des-Case DC-VG-2 Desiccant Breather
- Des-Case DC-VG-3 Desiccant Breather
- Des-Case DC-VG-4 Desiccant Breather
Browse all DES-CASE products on PE Energy Industrial Supply.
Related episodes
- DES-CASE KL Series Desiccant Breathers: How Steel Standpipe Design Handles Vibration and Harsh Environments
- DES-CASE Rebuildable Steel Breathers: How to Size and Rebuild RS-Series for Bulk Storage
- DES-CASE TDB Series Desiccant Breathers: How ZR Gel and 3 µm Filtration Protect Hydraulic Systems