---
title: "Chapter 4: Safety"
description: "![Manual image](/wp-content/uploads/2026/09/manual-image-011.png) Before working with any Corr-vac® machine, you should carefully read the manual. If you are not certain that you completely understand at any point which might affect the safe and/or reliable operation of this machine, do not proceed…"
url: "https://www.cv-tek.com/docs/mark-iii-plus/chapter-4-safety/"
updated: "2026-09-30"
category: Mark III Plus+
---

# Chapter 4: Safety

![Manual image](/wp-content/uploads/2026/09/manual-image-011.png)

Before working with any Corr-vac® machine, you should carefully read the manual. If you are not certain that you completely understand at any point which might affect the safe and/or reliable operation of this machine, do not proceed without getting competent assistance!

## 4.1. OPERATING THE MACHINE

**The following points are strictly forbidden:**

1. Do not operate this machine in an unsafe manner, for purposes other than those for which it has been designed and intended.
2. Do not connect the machine to any energy sources (electricity, compressed air and/or gas) unless the machine is fully assembled, with all protection and safety devices properly installed. This includes proper electrical grounding of the machine.
3. Do not turn on the electrical power at the machine if the rear doors are not closed and latched.
4. Do not use any gas or gas mixture containing anything but Carbon Dioxide or Nitrogen, in a standard Corr-vac^® machine. Use of poisonous, flammable or explosive gases is specifically prohibited.
5. Do not use any gas or gas mixture containing more than 21% Oxygen (by volume) unless the machine is specifically built for this purpose (designated by -O at the end of the machine's serial number).
6. If the machine is used with a high-Oxygen gas mixture, ensure that your supply hoses, pressure regulators, valves, etc. are suitable for Oxygen service.
7. Do not perform any maintenance, adjustments, repairs, etc. on this machine without first cutting off all energy sources. If this is impossible because of the work requirements, take all necessary precautions to protect yourself from injury.
8. Do not operate the machine if any guards, interlocks, or other safety devices are out of adjustment, broken, or missing. Under no circumstances should any of these devices be modified in any way.
9. Do not use two operators for a machine in order to avoid any possibility that one operator might accidentally start a machine function which would endanger the other operator.
10. Disconnect the machine from all energy sources when it is not being used.

## 4.2. USING THIS MANUAL

Throughout this manual the reader's attention is drawn to specific safety instructions as follows:

> **WARNING**
>
>
>
> A warning alerts the reader to a potential hazard. Failure to read and comply with the safety instructions may result in death or injury of personnel and damage to the machine or product.

> ****CAUTION****
>
>
>
> A caution alerts the reader to recommendations or instructions. The non-observance of which could cause damage to the machine or product.

> ****NOTE****
>
>
>
> A note provides additional information which should be given special attention.

## 4.3. DOOR OPENING INSTRUCTIONS

> **WARNING**
>
>
>
> - You cannot open the door unless the rotary disconnect switch is "OFF"
> - To close the door, the rotary disconnect switch must be "OFF", and the exterior red handle must also be in the "OFF" (horizontal) position

![](https://www.cv-tek.com/wp-content/uploads/2026/09/A91751d22_1epzdj0_t9s.png)

To open the upper cabinet door, follow these steps:

1. Release the black door latches, by turning them counter-clockwise, one quarter turn, to a vertical position.
2. On the red and yellow rotary electrical disconnect switch Ensure that the red handle is in the "OFF" (horizontal) position

## 4.4. DOOR CLOSING INSTRUCTIONS

To close the upper cabinet door, follow these steps:

1. On the red and yellow rotary electrical disconnect switch:
   - Ensure that the red handle is in the "OFF" (horizontal) position
   - Hold the release lever down, as you close the door (or the disconnect switch shaft will not enter the back of the door assembly)
2. Close the black door latches, by turning them clockwise, one quarter turn, to a horizontal position.

> **WARNING**
>
>
>
> - You cannot open the door unless the rotary disconnect switch is "OFF" and the release lever is held down
> - To close the door, the rotary disconnect switch must be "OFF", and the exterior red handle must also be in the "OFF" (horizontal) position and the release lever must be held down

![Manual image](/wp-content/uploads/2026/09/manual-image-016.png)

## 4.5. LOCKING CASTORS - INSTALLATION

Screw the castor's threaded stud up through the machine leg until the top of the castor is tight against the underside of the leg, then turn the lock nut tight against the top of the leg.

![Manual image](/wp-content/uploads/2026/09/manual-image-017.png)

> **WARNING**
>
>
>
> Never install the lock nut under the leg, as this will put more stress on the castor stud. Failure of this stud could cause the machine to tip over.

![Manual image](/wp-content/uploads/2026/09/manual-image-019.png)