APOLLO V4 KC-02 NPAS Power Adjustment Valve

Beta testing now complete, batch 1 available to order.

We have completed Beta testing with 7 KC-02's and mapped the performance to some extent, but please be aware this is a new experimental part - we cannot test every combination of barrel length, gas type and ammo weight at different power settings! We welcome your feedback.

Brief

• An NPAS is a power reduction device. 
• The Apollo V4 allows power adjustment of your KC-02 in the typical range of 2.5j to 0.60j, based on testing with 0.4g ammo across multiple barrels and gas types.
  • The 1.5j power output for DMR builds is typically around 4 turns open, or a 2.0mm gap.
• Shot-to-shot consistency is typically less than 10fps, though around 5fps deviation between shots is common. This is heavily dependant on the rest of your gun components.
• It comes with 2 rocket springs. We advise using the stronger spring which is the same as standard KJW spring #39. If you experience consistency problems, the weaker spring may help as the valve can close more easily.
• The Apollo V4 is made of purple-anodised CNC-machined 7075 aluminium for the body and 316 stainless steel for the base screw. Extremely high-grade materials for an airsoft component.

What's in the Bag

• Apollo V4 NPAS valve
• 2 x spare adjustment O-rings
• 2 x rocket springs (1 standard 0.055N/mm, 1 weak 0.0294N/mm)

Adjustment

Longer valve = Less power.

It is not recommended to open the Apollo valve more than 4.0mm (8 turns) where the first O-ring becomes exposed as the adjustment may become unstable.

The Apollo valve is intentionally very stiff to adjust with it's 2 O-rings on the screw stem so it cannot self-adjust in use. For this reason, we recommend disassembling your bolt carrier and removing the Apollo valve from it so you can gently grip the body with pliers while you twist the power screw back and forth with a small screwdriver to ensure precise adjustment. There is no adjustment tool supplied. Disassembly of the bolt and nozzle is very easy if you have a V14 RW bolt and V6 gold Genesis nozzle as all the pins are quick-release.

It is possible to adjust the Apollo without disassembling the bolt, by wedging the Apollo in place with a small Allen key or tweezers through the gas port of the nozzle, then twisting the power screw with a small screwdriver through the nozzle end. However, this is not a precise adjustment method and you may not be able to use the full range of the adjutsment. 

History and Development

We are pleased to announce the first NPAS (Negative Pressure Air System) valve developed specifically for the KC-02 platform.

The V4 Apollo valve follows on from everything we learnt from the V2 version in 2021, so we are happy to be reviving this design with new functionality. It will work with standard KC-02 nozzle and the Genesis metal nozzles, and all other versions of the KC-02.

If you don't know what an NPAS valve is, it is a method of power control for gas blowback rifles. It replaces parts #39 rocket valve and #40 spring in the KC-02, inside the nozzle. An NPAS adjusts the timing of how much gas released from the mag is split between sending the BB down the barrel and then activating the blowback to cycle the bolt assembly for the next shot. This ancient video from RA-Tech explains it well.

It features 2 locking O-rings on the adjustment screw thread to prevent self-adjustment in use. The screw thread is oversized to give it as much strength as possible to prevent the screw bending when stressed.

The Apollo V4 has a sealing O-ring on the outside of the valve which is very important for providing a gas seal during the blowback cycle of the gun, to ensure good snappy recoil and high gas efficiency is achieved.

Use with Flow Restrictors Not Recommended

The Apollo can be used at the same time as the Flow Chokes from our Genesis kits if you need a replacement rocket valve, but you won't be able to adjust the NPAS screw as the flow restrictors will block access to the screw. You do not need both. If you have an Apollo valve, then use of flow restrictors is redundant. Pick one or the other.