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TRANSCRIPT
Hi, I’m Todd with BlastOne here in Columbus, and today I’m going to show you how to replace a Teravalve seat on the bottom of the base.
Two major symptoms to watch for with a bad seat are:
1. Airflow without the Deadman being initiated, which should never happen.
2. Initiating the Deadman and immediately chugging a bunch of abrasive out of the blast hose before it evens out to the metering valve setting.
Both signs indicate that the Teravalve seat needs replacement.
Causes of these symptoms include positive or negative differential pressure, either from too much pressure in the pot or too much air through the push line without enough abrasive falling at the correct rate. Both issues cause the seal to wear faster.
The valve seal we’re after today is at the base of the Teravalve. If you look down here, you’ll see a dark purple urethane seal. That’s our target. You can see the whole plunger system and the dump channel, which should be plugged up.
The Teravalve mounts directly like this, with air coming down and no air escaping up due to the seal on the plunger. If there’s abrasive or air without a signal line initiated coming through, it could indicate a problem with the Teravalve. Today, we’ll focus on the valve seal at the bottom.
Here we have a dirty Teravalve from one of our MistBlasters. To replace the seal, remove these four 7/16 size bolts. Once these are off, you’ll have access to the bottom of the Teravalve. Sometimes the orifice will be oblong or oval-shaped from wear. This one looks good, but you can see where abrasive has caused extra wear on the base.
Next, we’ll access the actual seal on the bottom. It’s seated nicely into the machine slot. With a wrench or screwdriver, pry it out. When installing the new one, note the flat side goes towards the base, and the beveled edge goes around the plunger.
Discard the old seal to avoid confusion. The beveled edge on the Teravalve seat faces up towards the metering part of the valve. Clean the area, place the new seal beveled end up into the machine slot, and secure it.
Replace the 7/16 bolts and nuts, ensuring each screw has a washer on both sides. For easier access, place the nut on top with the bolt coming through the base. Tighten evenly.
And that’s how to replace a Teravalve seal. If you have any more questions, click the link below, and we can connect you with someone for further assistance.
