SF₆ DewGuard · DEW-30 · Compact Variant

Dry SF₆ Switchgear.
Without an outage.

A passive, in-service moisture absorber that bolts onto a standard gas-fill port and pulls water vapour out of energised SF₆ compartments — no power, no vacuum carts, no gas handling, no de-energisation.

Run the dry-down calc  → View specifications
<5 g
Gas loss per cycle
30 mL
Moisture capacity
0
Outages required
6–8 wk
Typical dry-down
SF6 DewGuard 30 mL compact variant
PASSIVE · NO POWER
DN8 / DN20 ADAPTER
MOLECULAR SIEVE · 30 mL
How it Works

Four ideas, one device.

SF6 DewGuard does one job — pull moisture out of energised SF₆ assets — and does it with no operator intervention while the equipment stays in service.

Zero Outages Required

Connects directly to the existing gas-fill port. Begins extracting moisture while the equipment stays fully energised and in service.

Passive & Always-On

Uses natural thermal circulation to draw moisture from the SF₆ gas phase. No power, no vacuum carts, no moving parts.

Pre-Pressurised Stability

Engineered to eliminate pressure drops on connection. Asset pressure stays stable — no sudden drops, no alarms.

Zero-Gas-Loss Cartridge

Proprietary self-sealing coupling enables desiccant cartridge replacement with less than 5 g of gas loss per cycle.

Live Demonstration

Watch moisture leave the chamber.

An animated representation of passive diffusion: H₂O molecules drift inside the SF₆ compartment, get drawn up through the coupling, and are captured by the molecular sieve. The ppmv reading drops in real time — each cartridge holds up to 30 mL of moisture before replacement.

Compartment moisture
400ppmv
▼ falling · target 150 ppmv (IEC 60480)
H₂O captured · lifetime
12.00mL
Cartridge fill
40%
Diffusion regime · 30 mL cartridge
L/min Q_eff · DN8 path · 20 kg SF₆ compartment
In Service

One port. Three principles.

SF6 DewGuard is engineered so that the act of connecting it doesn't disturb the asset it's drying.

SF6 DewGuard connection to switchgear flange
01

Pre-Pressurised Engagement

Designed to maintain absolute asset pressure stability upon connection. No sudden pressure drops or operational alarms.

02

Passive Diffusion Engine

Natural thermal circulation inside the asset continuously draws moisture into the molecular-sieve phase — no mechanical pumps.

03

Self-Sealing Coupling

Guarantees less than 5 g total SF₆ loss across fitment and removal, with a dry coupling and standard procedure.

04

Hand-Tightened, Removed By Hand

No power tools required. The integrated check-valve opens automatically when the coupling is fully engaged.

Technical Specifications

DEW-30 · The numbers.

The 30 mL compact variant — sized for circuit breakers, instrument transformers and small bus compartments. Short-residency drying campaigns of 2–10 weeks; permanent fit for ongoing moisture control.

Mechanical

Model
ITS-DEW-30
Housing material
Anodised aluminium 6000-series, powder-coated black
Coupling material
Brass / aluminium with EPDM/Viton seals
Fasteners
Stainless steel A2-70
Desiccant media
Molecular sieve, tuned for SF₆ service
Desiccant volume
30 mL nominal per cartridge
Water capacity
≈ 30 g H₂O at 25 °C, full saturation
Dimensions (W × H)
Ø 82 mm × 116 mm (excl. adapter)
Net weight
1.20 kg ± 0.10 kg (with cartridge)
Service position
Any orientation; vertical preferred

Performance

Operating principle
Passive diffusion · molecular-sieve adsorption
Compatible gases
SF₆, SF₆/N₂ blends, dry air, CF₄ blends
Service pressure
0.1 – 10.0 bar gauge
Max. working pressure
50.0 bar gauge
Operating temperature
−40 °C to +70 °C ambient
Storage temperature
−20 °C to +50 °C (sealed)
Residency
Permanent fit for ongoing moisture control
Indicative dry-down
≈ 400 → ≈ 150 ppmv on 20 kg SF₆ in 6–8 wk @ 25 °C
Pressure drop in service
Negligible — passive coupling
Gas loss per cycle
< 5 g (dry coupling, standard procedure)
Connection Options

One housing. Every asset.

Ships with a user-selected coupling adapter. Field-swap adapters lets a single SF6 DewGuard serve multiple asset types across the substation.

Adapter CodeCompatible Coupling StandardDefault Stock
DEW-30-A-DN8DN8 self-sealing coupling (DILO-style 3-8200)In stock
DEW-30-A-DN20DN20 self-sealing coupling (DILO-style 3-2002)In stock
DEW-30-A-AQAeroquip-style quick-disconnectOn request
DEW-30-A-RECTRectus-style couplingOn request
DEW-30-A-NPT⅛" / ¼" NPT threaded portOn request
Planning Tool

SF₆ Dry-Down Calculator.

Estimate the residency time required to reach a target moisture level. Built on the planning formula t ≈ (V / Q_eff) × ln(x₀ / x_f) with the three published Q_eff regimes for the DEW-30 unit on a typical DN8 path.

kg
0.5 kg200 kg
ppmv
ppmv
°C

Estimated Residency Time

For a 20 kg SF₆ compartment, dropping from 400 ppmv to 150 ppmv, expect:

Best caseHigh temperature, large coupling, clear convection
— d
— weeks
Typical25 °C, standard DN8 path, normal load
— d
— weeks
ConservativeCold ambient, restricted coupling geometry
— d
— weeks
Note · Planning estimate only. Actual performance depends on compartment volume, baseline moisture, pressure, temperature and connection geometry. Always verify the final moisture level with a calibrated portable hygrometer before closing out the job.
SF₆ Behaviour
Water in SF₆ exists almost entirely in the gas phase at service pressures — temperature lowers it into the dew point. Drying the gas keeps you well above the cold-spot dew point.
IEC 60480 Reference
Re-use of SF₆ is permitted when moisture is below ≤ 200 ppmv (≈ 25 ppmw at 1 bar). Margins are recommended for assets that cycle in temperature.
CIGRE Guidance
TB 234 / TB 567 give moisture action levels for in-service switchgear. DewGuard residency planning should target levels comfortably below the action threshold.
Installation Guide

Eight steps. No outage.

For trained substation maintenance personnel only. Always follow site safety procedures and your employer's approved permit-to-work protocols.

Verify the asset's gas-fill port type and select the matching SF6 DewGuard adapter before going to site.

Record baseline moisture (ppmv), compartment pressure (bar) and ambient temperature (°C) using a calibrated portable SF₆ hygrometer. Log values on the installation label.

Confirm the cartridge service window has not been exceeded by checking the date code on the cartridge wrapper. Use only sealed cartridges within their shelf life.

Wipe the gas-port mating face clean. Inspect the adapter O-ring for damage. Do not lubricate.

Hand-tighten SF6 DewGuard onto the gas port. Do not use power tools. The integrated check-valve opens automatically when the coupling is fully engaged.

Affix the installation label to the asset for site visibility. Note the planned removal date.

Leave the unit in service for the planned residency period. No further intervention is required during this time.

At the end of residency, repeat the moisture reading from a separate test port. Disconnect by hand; replace the cartridge before redeployment.

Standards & Compliance

Built around the references that matter.

IEC 60480

Specification and acceptance criteria for SF₆ in service.

IEC 62271-4

High-voltage switchgear handling procedures for SF₆.

CIGRE TB 234 / 567

Reference for SF₆ moisture limits in switchgear.

ISO 9001

Manufactured under ISO 9001 quality management (certification in progress).

About · Infinitee Techsol

Built by engineers who have lived inside SF₆.

SF6 DewGuard is the work of a Pune-based engineering team with 30+ years of combined experience across high-voltage SF₆ switchgear, substation maintenance, gas-handling field operations and asset-management for utilities and industrial owners.

The team has spent decades on real substations — commissioning, decommissioning, troubleshooting moisture and decomposition issues, supervising gas handling crews and writing the procedures that keep SF₆ assets healthy through their service life. SF6 DewGuard is a product built from inside that world, not designed at a desk.

We chose passive diffusion because every other answer asks the asset owner to take their plant out of service. Our answer is to make moisture management a routine, in-service activity — without an outage, a vacuum cart, or a gas-handling crew.

30+
Years of team experience
100%
Passive operation
IEC
Standards-aligned
India
Designed & built
SF6 DewGuard installed on energised substation asset
In service DEW-30 installed on an energised substation asset — power transformer in the background.
Get in Touch

Request a quote or talk to engineering.

Tell us a little about your asset base and we'll come back with pricing, lead time and an adapter recommendation.

Manufacturer
Infinitee Techsol Private Limited
Address
69, Aditya Shagun Mall,
NDA-Pashan Road,
Pune – 411 021, India
Email
solutions@infiniteetechsol.com
Phone
+91 99230 81478
Web
www.sf6dewguard.com
www.infiniteetechsol.com
Registration
CIN · U74999PN2020PTC191912
GSTN · 27AAFCI6968R1ZH
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