APL Valve for GE Anesthesia Machines: Selecting the PN by Model

The APL valve (Adjustable Pressure Limiting) is one of the key safety elements of an anesthesia machine. It allows the anesthesiologist to manually set the upper pressure limit in the breathing circuit and instantly vent excess gas into the scavenging system. A faulty APL valve during manual bag ventilation can lead to barotrauma of the patient's lungs.

Four different APL valves are produced for the GE Datex Ohmeda anesthesia machine line — one for each main series. In this article we look at their purpose, differences, signs of failure and selection rules.

Short answer

The APL valve (Adjustable Pressure Limiting) is an adjustable pressure limiting valve in the breathing circuit of an anesthesia machine: it sets the upper pressure limit during manual ventilation, and excess gas goes into the waste gas scavenging system. Three signs help you understand that the valve needs replacing: a leak in the circuit persists even at the minimum regulator position, the cap turns with binding or grinding, the machine self-test issues an APL test error. Selection is made only by machine model: for AESPIRE 7100, Aestiva, Carestation 600 Series and Aelite NXT these are four different part numbers — 2106569-001-s, 1406-8202-000-S, 2090000-001-S and 2100552-001-S respectively. Check the model on the nameplate on the rear panel and take the PN from the table below; the APL membrane 1406-3331-000 is supplied as a separate item.

1. How the APL works

The APL is installed on the patient's expiratory side, between the circuit and the manual ventilation bag. Turning the adjustment cap changes the force of the spring pressing the valve against the seat:

When the set pressure is exceeded, the valve automatically vents gas into the waste gas scavenging hose (AGSS / scavenging).

2. Technical specifications of the four GE APL valves

3. Machine model ↔ PN

The table contains only the "machine model — item" pairs that are in our compatibility database with the status "confirmed": the correspondence of the machine model to each part number has been verified manually.

There is no confirmed compatibility record for the APL membrane with a specific model in our database: for it, the table shows applicability per manufacturer data (GE Aestiva) — this is a source reference, not a confirmed link. The correspondence to a specific machine is confirmed by PN.

If your machine is not in the table, check the nameplate on the rear panel against the GE service documentation. The Avance and Aisys lines use other PNs (not covered in this article).

4. When to replace the APL valve

Three characteristic signs of failure:

1. Leak at the minimum position. You turn the cap all the way counterclockwise (minimum position), but a hiss is still audible in the circuit — the valve seat is worn and replacement is required.
2. Difficult cap rotation. Normally rotation is smooth, with slight spring resistance. If rotation has become abrupt, with binding, or grinding is heard — thread corrosion, replacement is required. The assembly should not be lubricated: under GE regulations, APL valve service does not include lubrication.
3. APL test error during machine self-test. Most modern GE machines automatically check APL tightness when switched on. If the test is not passed — replacement.

What to check before replacement

Before ordering a valve, it is worth ruling out adjacent causes of the same leak:

During replacement

Work is carried out with the machine switched off and circuit pressure released. The valve is installed without force, without wrapping or lubricating the thread: under GE regulations, APL valve service does not include lubrication. After installation, run the machine self-test — the APL test must be passed, and with the circuit closed the pressure gauge must hold the set pressure.

5. Common mistakes

Attempting to install a "similar" APL from another model. The threads, seat diameters and outlet port orientation are different on all 4 models. If you physically try to install an unsuitable valve, you can damage the seat on the machine — the repair will cost more than buying the correct APL from the start.

Flushing the valve with water or disinfectant. Water leaves mineral deposits on the valve seat.

Lubricating the cap thread. Under GE regulations, APL valve service does not include lubrication — the assembly should not be lubricated; for circuit O-rings GE separately specifies Krytox lubricant.

Ignoring an APL test error during self-test. The machine may continue to operate, but the valve in fact does not perform the pressure limiting function. Risk of barotrauma.

Confusing PN 2106569-001-s (Aespire) vs 1406-8202-000-S (Aestiva). Both are used on GE anesthesia machines, both are of the 4-digit series, but they are not interchangeable.

6. Where to buy original APL valves

MediAccessori supplies all four models of GE Datex Ohmeda APL valves — 2106569-001-s, 1406-8202-000-S, 2090000-001-S and 2100552-001-S — to Russia and the CIS countries with a lead time confirmed when the order is placed. The associated APL membrane 1406-3331-000 is supplied as a separate item. When ordering, be sure to specify the anesthesia machine model and the last 4 digits of the serial number — the manager will check against the nameplate and select the correct PN. Availability is confirmed when ordering. Contact — Telegram @GEpartsV_bot.

Sources: GE Healthcare, Aestiva Anesthesia Machine Technical Reference Manual (1006-0452-000), §2.3.2 "APL Valve"; §3.11 "Breathing system tests"; §5.2.2 "Every twelve (12) months"; §5.4 "Dressing leaky seats in bellows pop-off and APL valve". Datex-Ohmeda, 7100 Anesthesia Ventilator Technical Reference Manual (1006-0836-000), Fig 9-4. MediAccessori's own experience with supplies in 2024–2026.