Gig103 Senior Member Joined: 12 Feb 2012 Posts: 255 Location: Arizona Expertise: I like coffee
Espresso: Crossland CC1 Grinder: Baratza Vario Drip: French press!
Posted Wed Jul 25, 2012, 12:41pm Subject: Backflushing and the OPV
I was wondering - if I am backflushing, and let the pressure build up too much before I shut off the pump, might the detergent make its way into my reservoir? SCG put out a new 'tip sheet' on their FB page that recommended leaving the pump on for 15 seconds which seems awfully long.
Posted Wed Jul 25, 2012, 12:58pm Subject: Re: Backflushing and the OPV
The OPV is between the pump and boiler (this is so only cold water is returned to the reservoir, as hot water can damage vibe pumps). The PF/group is pressurised through the OPV and boiler, and so can't be at any higher pressure than the boiler (and will be slightly below the boiler pressure if there's any kind of leak around the group), and so there can't be any significant flow back into the boiler. In turn, there isn't any flow back from the boiler to the OPV, so there's no risk of backflush detergent entering the reservoir.
At least this is the case on my Gaggia Classic. I'm sure there's one machine or another that does it differently.
Symbols: = New Posts since your last visit = No New Posts since last visit = Newest post
Forum Rules: No profanity, illegal acts or personal attacks will be tolerated in these discussion boards. No commercial posting of any nature will be tolerated; only private sales by private individuals, in the "Buy and Sell" forum. No SEO style postings will be tolerated. SEO related posts will result in immediate ban from CoffeeGeek. No cross posting allowed - do not post your topic to more than one forum, nor repost a topic to the same forum. Who Can Read The Forum? Anyone can read posts in these discussion boards. Who Can Post New Topics? Any registered CoffeeGeek member can post new topics. Who Can Post Replies? Any registered CoffeeGeek member can post replies. Can Photos be posted? Anyone can post photos in their new topics or replies. Who can change or delete posts? Any CoffeeGeek member can edit their own posts. Only moderators can delete posts. Probationary Period: If you are a new signup for CoffeeGeek, you cannot promote, endorse, criticise or otherwise post an unsolicited endorsement for any company, product or service in your first five postings.