A Purpose-Built Connector for Filling Medical Oxygen Cylinders

The FasTest MediMate® G870 is a connection tool built for one job and built well for it: filling medical oxygen cylinders through CGA-870 valves. CGA-870 is the post-yoke, pin-index connection used on small and portable medical oxygen cylinders — the pin-index safety system that keys each gas to its own connection so the wrong gas cannot be connected. The MediMate® G870 makes an instant, fast, repeatable connection to those valves for the volume of a medical gas fill operation.

Because it handles medical oxygen, it is built to the requirements oxygen and medical service impose. It is cleaned for O2 service, so the connector is free of the hydrocarbons and oils that must be kept out of any oxygen system. Its seals are FDA-grade Viton® (FKM) elastomer, appropriate for medical gas contact. And a positive-pressure internal safety mechanism prevents the tool from being removed while the cylinder is under pressure. These are not add-ons — they are what make a connector fit to fill medical oxygen.

The connection itself is a lever-handle actuation onto the CGA-870 post-yoke valve: fast to make, repeatable across a shift of cylinders, and secure under pressure. The tool is rated from vacuum to 3600 psi (250 bar), covering the fill pressures of medical oxygen cylinders.

For a medical gas filler, that combination — the right CGA-870 yoke connection, oxygen-clean construction, medical-grade seals, a fast lever connection, and a safety mechanism against removal under pressure — is what a purpose-built medical oxygen fill connector should be, rather than a general-purpose tool pressed into medical service.

The Problem the FasTest MediMate® G870 Solves

Filling medical oxygen cylinders places demands a general gas connector does not meet:

• The connection must be the medical standard: Small medical oxygen cylinders use CGA-870 post-yoke pin-index valves. The tool connects to exactly that — the pin-index keying is a safety feature, not a detail.
• Oxygen demands clean equipment: Oils and hydrocarbons must be kept out of oxygen systems. The connector is cleaned for O2 service so it does not introduce them.
• Medical gas needs appropriate materials: The seals are FDA-grade Viton® elastomer, suited to medical gas contact.
• Filling is high-pressure and repetitive: A fill line runs cylinder after cylinder at high pressure. The tool makes fast, repeatable lever connections and cannot be removed under pressure.

The FasTest MediMate® G870 answers each: a CGA-870 post-yoke connection, cleaned for O2 service, with FDA-grade seals, a fast lever actuation, and a positive-pressure safety mechanism, to 3600 psi.

Key Features 

CGA-870 Post-Yoke Pin-Index Connection

The tool connects to CGA-870 post-yoke pin-index valves — the connection on small and portable medical oxygen cylinders. The pin-index safety system keys the connection to oxygen, so the tool mates only with the correct valve, and it makes that connection instantly for fast cycling through cylinders.

Cleaned for O2 Service

The connector is cleaned for oxygen service — free of the oils and hydrocarbons that must be kept out of an oxygen system, because in high-pressure oxygen those contaminants are an ignition hazard. This is a core requirement for any tool that touches medical oxygen, and it is built in. Oxygen filling should always follow FasTest’s operating instructions and applicable oxygen-handling standards.

FDA-Grade Viton® Elastomer Seals

The seals are FDA-grade Viton® (FKM) elastomer, a material appropriate for medical gas contact. The seal is what makes the connection leak-tight, and using an FDA-grade material is part of making the tool fit for medical oxygen.

Positive-Pressure Safety Mechanism

A positive-pressure internal safety mechanism prevents the tool from being removed while the cylinder is under pressure. On a high-pressure oxygen fill, a connection that could be pulled off under pressure is a serious hazard; this mechanism does not allow it.

Fast, Repeatable Lever-Handle Connection, to 3600 psi

A lever-handle actuation makes the connection quickly and repeatably — suited to the volume of a fill line — and the tool is rated from vacuum to 3600 psi (250 bar), covering medical oxygen cylinder fill pressures.

Technical Specifications

Where the FasTest MediMate® G870 Is Used

Medical Oxygen Cylinder Filling

Its core use is filling medical oxygen cylinders — connecting to the CGA-870 post-yoke valve, filling, and disconnecting, cylinder after cylinder, on a medical gas fill line.

Small and Portable Oxygen Cylinders

CGA-870 is the connection on small and portable oxygen cylinders — the kind used for patient and portable medical oxygen — so the MediMate® G870 is the tool for filling that class of cylinder.

Medical Gas Filling Operations

In a medical gas filling operation, the combination of oxygen-clean construction, FDA-grade seals, and a fast, safe connection suits the tool to production filling where cleanliness and repeatability both matter.

Medical / Life Science and Compressed Gas

The MediMate® line sits at the meeting point of FasTest’s medical / life science and compressed gas work — medical gas filling — where the connector serves oxygen supply for healthcare.

FasTest MediMate® G870 vs. a Conventional Manual Yoke Connection

Frequently Asked Questions

Q: What is the MediMate G870?

A: It is a FasTest medical oxygen fill connection tool for CGA-870 valves — the post-yoke pin-index connection on small and portable medical oxygen cylinders. It makes fast, repeatable connections for filling, is cleaned for O2 service, uses FDA-grade Viton® seals, and is rated to 3600 psi.

Q: What is a CGA-870 connection?

A: CGA-870 is the post-yoke, pin-index connection standard for small medical gas cylinders. The pin-index safety system keys each gas to its own pin pattern so the wrong gas cannot be connected — which is why it is the standard for medical oxygen. The MediMate® G870 connects to CGA-870 oxygen valves.

Q: Is the MediMate G870 cleaned for oxygen service?

A: Yes. It is cleaned for O2 service — free of the oils and hydrocarbons that must be kept out of oxygen systems, since in high-pressure oxygen those contaminants are an ignition hazard. Oxygen filling should always follow FasTest’s operating instructions and applicable oxygen-handling standards.

Q: What seals does it use?

A: FDA-grade Viton® (FKM) elastomer seals, a material appropriate for medical gas contact.

Q: Is it a yoke-style connector?

A: Yes — it connects to the CGA-870 post-yoke pin-index valve with a lever-handle actuation, so it is a yoke-style oxygen connector for medical cylinders.

Q: Can it be removed while under pressure?

A: No. A positive-pressure internal safety mechanism prevents the tool from being removed while the cylinder is under pressure.

Q: What pressure is it rated for?

A: Vacuum to 3600 psi (250 bar) — covering medical oxygen cylinder fill pressures.

Q: Is it a quick connect?

A: It makes an instant, fast, repeatable connection to the CGA-870 valve for filling, then releases — a reusable quick-connecting fill tool, not a permanent coupling left on the cylinder.

Q: What does it connect to?

A: Post-yoke pin-index compressed gas valves to the CGA-870 standard — medical oxygen cylinder valves.

Q: Who uses the MediMate G870?

A: Medical gas fillers — operations that fill medical oxygen cylinders — across the medical / life science and compressed gas industries.