Guide for Valve/ Valve Repair/ Valve Replacement Parts

Our most popular Schmidt (Axxiom) portable blasters are the 1.5, 3.5, and 6.5 cu. ft. blast pots (vessels). They are often purchased as a package but components are also sold separately, as well as replacement parts and repair kits. Below is information to assist you with valves and valve parts replacement.

If you need parts for a 10 cu. ft or larger blaster, bulk blaster, M-series, Accustrip/soda blaster, mini-blaster, portable blaster with an atypical or customized configuration, or you have questions about your system, please contact our knowledgeable staff to assist you with your replacement parts purchase. info@nortonsandblasting.com

For standard Micro Valve-ComboValve (MV/MV2) or Thompson Valve (TV/TVII) portable blasters in sizes 1.5, 3.5 or 6.5 cu. ft. (electric or pneumatic), use the following as a guide for valves and valve parts:

MV= MicroValve (original, orange knob) Buy Online!
MV2= MicroValve II (MV2, blue knob) Buy Online!
TV= Thompson Valve (original, orange knob) Buy Online!
TVII= Thompson Valve II (blue knob) Buy Online!

All of these valves can easily be fitted for use with other manufacturers' blasters.

MV/MV2= "automatic blowdown" or "pressure release" system
TV/TVII= "manual blowdown" or "pressure hold" system

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Click here to view diagrams

FAQ:

How do I determine if my blaster has a MicroValve/MV2 or a Thompson Valve/TVII?

If there is a 1/4" control hose attached to the valve in addition to the pusher air line, it is a TV (orange knob) or TVII (blue knob). This extra air line opens the normally closed valves when the Deadman is activated and is not present with MV/MV2 systems. In most cases, there will not be a ComboValve when using a TV/TVII. If your blaster automatically depressurizes when you release the Deadman Control (automatic blowdown), it is a MV/MV2-ComboValve system. If your pot remains pressurized until you manually exhaust the pressure (manual blowdown), you have a TV/TVII system. Both the MV and the TV (older/original styles) have an orange knob. Both the MV2 and the TVII (newer style with added features) have a blue knob.

I have a MV. Can I replace it with an MV2? Why would I choose the MV2? Will I need an adapter or conversion kit?
You can use an MV2 in place of an MV. No adapter or conversion kit is needed unless you have 1" pusher line piping. We do not sell a 1" MV2; however, a simple reducing fitting can be used to adapt a 1" pipe system to the MV2. The MV2 has several improvements over the MV. It has a Virtual Position Indicator for user-friendly, precise and consistent abrasive flow, an improved cleanout, and is made of durable Carbon Steel (MV is Aluminum). Click here for the pdf comparison chart.

I have a TV. Can I replace it with an TVII? Why would I choose the TVII? Will I need an adapter or conversion kit?
You can use a TVII in place of a TV. No adapter or conversion kit is needed. The TVII has several improvements over the TV. Click here for TVII information (pdf).

What is the difference between the MicroValve and the Thompson Valve and are they interchangeable?
The MicroValve system (MV2) is a "Normally Open" valve. It is typically used in conjunction with a ComboValve. It is more commonly used because it has a lower initial cost than the TV/TVII valve system. The MV/MV2 system will automatically depressurize when the Deadman is released (also called pressure release or automatic blowdown system). In contrast, the TV/TVII is a "Normally Closed" system that remains pressurized (manual blowdown.) Both use a Deadman Control. The TV/TVII system is much more efficient and cost effective because the pot remains pressurized until you release the exhaust valve manually. Maintaining pressure reduces downtime, reduces abrasive media waste, and reduces costs associated with repressurizing to pot. One of the most significant costs in blasting is the energy used to repressurize the pot, especially as the media level gets low in the vessel and more air is needed to reach the required pressure. In MV/MV2 systems, there is more loss (downtime and media waste), as the pot must reach the appropriate pressure and equalize before there is consistent abrasive media flow. MicroValve and Thompson Valve systems are NOT readily interchangeable. A do-it-yourself conversion kit may be used to modify a MV/MV2 system to a TV/TVII. Please contact us if you want more information about conversion. info@nortonsandblasting.com

What is the difference between the TV/TVII Tungsten Carbide and Urethane insert and can I choose which I prefer to use?
Tungsten Carbide TV/TVII valves last longer and cost more. If you blast with steel grit and use a TV valve, you must use the Urethane insert type to ensure proper media flow (this is not an issue with the TVII). Otherwise, the choice is yours.

What is an Abrasive Cutoff (ACO) Switch?
The ACO is an optional switch used with TV/TVII systems that allows you to close the grit valve and continue to "blast" with just compressed air. This provides a quick and easy way to clear the blast hose and blasting area of abrasive.

Is the Deadman Control different for MV/MV2 and TV/TVII systems?
No. The same G2 Deadman Control is used for either type. However, you must choose either the Electric or Pneumatic Deadman G2 Control. Pneumatic Deadman Controls are configured for the twinline hose. The old style Deadman Control (SM2263-000) is obsolete and is replaced with the Deadman G2 (SM2263-002 Pneumatic or SM2263-402 Electric). A long style Deadman Control is also available (SM2263-001 pneumatic).

How do I know what size TV/TVII to buy?
TV/TVII valves are sold in three sizes: 1", 1-1/4" and 1-1/2". The 1" valve has 1-1/2" male threads on one side and 1" female threads on the other side of the base/pipe nipple. The 1-1/4" valves have 1-1/4" male threads on both sides of the pipe nipple. The 1-1/2" valves have 1-1/2" male threads on both sides of the pipe nipple.

How do I know what size MV/MV2 to buy?
MV valves are sold in 3 sizes: 1", 1-1/4" and 1-1/2". One side of all sizes is 1-1/2" pipe (base nipple) with male threads. The other side (inlet) is either 1", 1-1/4" or 1-1/2" NPT. The 1" has female threads. The 1-1/2" and the 1-1/4" have male threads. You should purchase the size that fits your blaster's pusher air hose. The MV2 is sold in two sizes: 1-1/4" and 1-1/2". One side of both is 1-1/2" with male threads. The other side (inlet) is either 1-1/4" or 1-1/2" NPT male threads. You should purchase the size that fits your blaster's pusher air hose. If you have a 1" pusher line and would like to use the MV2, you can use a reducing fitting. Click here for MV2 part numbers and images.

Are parts different for pneumatic and electric blasters?
Many parts are the same for both pneumatic and electric: vessel (pot) parts such as sealing rings, plunger, gaskets, TV/TVII, MV/MV2. The Deadman Control is specific, as well as a few other control parts. Pneumatic systems use twinline hose. Click here for the list of parts diagrams (select pneumatic or electric from the list).

How does the MicroValve-ComboValve work?
Currently, standard Schmidt portable blasters use a MicroValve 2 (MV2), ComboValve, and Deadman Control (G2). This configuration is referred to as an "auto blowdown" or a "pressure release" system. With this system, you use the Deadman Control to activate the ComboValve, which simultaneously opens the inlet and closes the exhaust to allow the pot to pressurize. It depressurizes automatically when the Deadman control is released. If you have an older system, it may have a MV instead of an MV2. You may replace your MV with an MV2 to take advantage of the improvements in valve life, flow rate, cleanout port, etc. Click here for the pdf comparison chart. The MV2 comes in 2 sizes- 1-1/4" NPT or 1-1/2" NPT. This refers to the inlet side (connects to the pipe on the pusher line side). Both valves are 1-1/2" inches on the other side. Choose the appropriate size for your blaster, as this can vary and is not necessarily dependent on the pot size. Click here for part numbers and images. The MV2 is not available with a 1" inlet. If your system uses a 1" pusher line, use a 1" MV or use a reducing fitting to adapt the MV2. Note that numbers stamped on the valve may be machine markings or may refer to a specific part of the valve and not the entire valve. Complete valves, repair kits, and parts are available for the MV, MV2, ComboValve and Deadman G2.
Click here to view parts diagrams.
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How does the Thompson Valve (TVII) work?
The TV and TVII are "normally closed" valves with a manual blowdown (also known as a "pressure release" system). A G2 Deadman is used to control the normally closed valves (Automatic Air Valves also known as Aquamatic) and the normally closed TV/TVII valve to pressurize the blast pot. Unlike MV/MV2 systems, when you release the Deadman Control, the blast pot remains pressurized until you the exhaust the pressure manually. Maintaining pressurization reduces downtime, abrasive media waste, and costs associated with repressurizing the pot. One of the most significant costs in blasting is the energy used to repressurize the pot, especially as the media level gets low in the vessel and more air is required to establish the proper pressure. TV and TVII valves are available with Tungsten Carbide (lasts longer) or Urethane inserts. Note that with a TV, you should use the Urethane insert style when blasting with steel grit to ensure proper media flow (only with the TV, not the TVII). TV and TVII valves are available in 1", 1-1/4" and 1-1/2" NPT sizes, which refer to the inlet side and you should choose the size that fits your pusher line pipe. The 1" TV/TVII has internal female threads on the inlet side and 1-1/2" external male threads on the other side. Note that numbers stamped on the valve may be machine markings or may refer to a specific part of the valve and not the entire valve. TVII valves are also available in Key-Slot (for use with the M-Series blasters) and Multiport (for use with Accustrip Soda blasters). Complete valves, repair kits, and parts are available for the TV, TVII, and Deadman G2.
Click here to view parts diagrams.
Click Here to Buy Parts Online