The PMK-1 (Russian: Противогаз Mалогабаритный Kомбинированный – "Compact Combined Mask"), also designated as GP-7VM for civilian use, is the first mask in the PMK series. First made in 1970(also the year in which its first prototype was made) and entered mass production in 80s. Was adopted by Soviet Union in its final years, later receiving some use with the armed forces of the Russian Federation.
The PMK-1 represented a break from the 'helmet' style design which had been favoured for so long in the Soviet Union, using the same GOST 40mm threaded (Kr40h4 in accordance with GOST 8762 -75) filters as most other Soviet masks.
After several years of service, the PMK-1 would eventually be replaced by the PMK-2 respirator in the early 90s. Due to the PMK-1 mask being relatively similar to the PMK-3, it is still used today in Russia as a training gas mask.
It should be noted that a left-handed model of the PMK-1 respirator exists. It's somewhat rarer compared to the right-handed model. This mask can be identified by the presence of the only filter port on the right cheek, instead of the left cheek (for shooting right-handed).
Known to come in two variants, the PMK-1 was originally manufactured with all the metal parts colored black: eyepiece frames, voice emitter as well as the lens outserts. A second version, sometimes referred to as the GP-7VM featured unpainted light-gold colored metal parts. A first Soviet mask to feature triangular lenses.
PMK-1s come in three sizes, denoted by the number 1, 2 or 3 (size ascending) encircled on the opposite side to the inlet. Directly underneath is the Т prefixed year of manufacture, and the Ф prefixed mould number.
A first mask of Soviet Union to feature drinking system. Drinking with the gas mask worn is made possible with the use of a drinking tube which is fixed on the mask. The drinking tube is wrapped around the voice diaphragm cover and the tip pushed into its retainer to the rear of the exhale valve when not in use. The shuttle valve cap needed to use the drinking tube is issued with the mask.
The mask mounts a filter on the side of the cheek with the voice emitter and filter port secured to the mask by metal ring clamps. These ports do not use adhesives and as a result, with a certain degree of tinkering, are interchangeable.
Consistent with other Soviet masks, the PMK-1 uses two exhale rubber discs which may increase breathing resistance to a certain extent but slightly improves protection.
The inlet has a simple plastic cover inside, directing the intake towards the user's nose and mouth. Lacking an oral-nasal cup, or the tissot tubes of previous masks, it has a tendency to fog. For this reason, anti-fog inserts were issued with the PMK-1.
It is unclear what type of rubber was used to make the face piece but it appears to be butyl; which allows for a low-cost construction and resistance to acid gases .
A PMK-1 kit is known to contain the following items:
1.) Carry bag
2.) Pace Piece M-80
3.) Insulating lenses
4.) Hydrophobic knitted filter sock (used as a particulate filter and snow cover)
5.) EO.1.08.01 (in olive-drab color; uses GOST 40mm thread)
6.) Anti-fog inserts in a tin (rounded-triangular)
7.) Drinking bottle with shuttle valve cap (optional)
9.) Spare drinking tube