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LNS Seachoice 20991 Aluminum Anti Siphon Valve 1/4" NPT Thread, 3/8' ID Hose Barb P12483455LNS-50-20991 https://cdnimages.opentip.com/full/LNS/LNS-50-20991.jpg Seachoice 20991 Aluminum Anti Siphon Valve 1/4" NPT Thread, 3/8' ID Hose Barb Manufacturer Part Number: 20991Coast Guard industry standards require anti-siphon protection on all gasoline powered boats. This valve combines anti-syphon protection with a convenient hose barb design. Made of corrosion resistant aluminum.Thread: 1/4\" NPTHose: 3/8\" ID 12483455 719249209913 0.2500lbs 0.75 2.00 5.00
Seachoice
8.7900 2027-07-05 1618 In Stock
customer review - by , November 11, 2025
5/ 5stars
Exactly what I ordered, arrived on time, and the price was right.
customer review - by , September 9, 2025
4/ 5stars
Easy to install and fit just right.
customer review - by , August 8, 2025
4/ 5stars
Threads where good .
customer review - by , July 7, 2025
5/ 5stars
Thank God for electric fuel pump, bleeds back be there a month of Sundays with a mechanical pump
customer review - by , July 7, 2025
3/ 5stars
Thank God for electric fuel pump, bleeds back be there a month of Sundays with a mechanical pump
customer review - by , November 11, 2024
5/ 5stars
I am doing a repower on my old 1993 Sea Nymph 190 Stinger deck boat, and I decided brand new fuel lines were in order. I had a impossible time reaching into a small space to get a proper 3/8 USCG rated fuel line to slide onto my old fitting, but I was able to remove it, cleaned it, and found it was sized for more like a 7'16 hose. Searching for a replacement bought me to choosing this item, it is more expensive than others here, but, looked to be of good quality. The pictures show it is well made, sized more for a 3/8 hose, and has well machined 1/4 NPT threads that match the old fitting exactly. Blowing air into it definitely tested its ability to check flow in one direction. I will be installing this very soon to get the boat back in service.
customer review - by , March 3, 2024
5/ 5stars
It's an exact replacement for my 1998 Bayliner 19 foot 1950 CL inboard-outboard. It attaches to the top of the fuel tank. It's a one-way valve, allowing fuel to go toward the engine, but prevents siphoning if a hose should break. My old one was functional but badly corroded.
customer review - by , November 11, 2023
5/ 5stars
Fit perfectly, and now my boat doesn't bog down when going WOT.
customer review - by , October 10, 2023
5/ 5stars
Fit perfectly, just be careful not to over tighten, it's Aluminum and will snap, hence why I bought this one lol
customer review - by , October 10, 2023
5/ 5stars
chicken dinner

Seachoice 20991 Aluminum Anti-Siphon Valve 1/4" NPT Thread, 3/8' ID Hose Barb, Price/Each

stars Rating 5 | 20 reviews
Brand Seachoice
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UPC: 719249209913
SKU: LNS-50-20991
Price: $8.79
Quantity:
1618 In Stock
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Product Description

Price is for Each.

Manufacturer Part Number: 20991

Coast Guard industry standards require anti-siphon protection on all gasoline powered boats. This valve combines anti-syphon protection with a convenient hose barb design. Made of corrosion resistant aluminum.

Thread: 1/4" NPT
Hose: 3/8" ID

warning tips WARNING: This product can expose you to chemicals which are known to the State of California to cause cancer, birth defects, or other reproductive harm. For more information, go to www.p65warnings.ca.gov.

Note

This product is not eligible for coupon code discount, for we've been offering the best price in the market.
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Customer Reviews
By rrs209
Date: November 10, 2025
Exactly what I ordered, arrived on time, and the price was right.
Rating: 5 stars [5 of 5 Stars!]
By sparky
Date: September 05, 2025
Easy to install and fit just right.
Rating: 4 stars [4 of 5 Stars!]
By Todd Andrews
Date: August 06, 2025
Threads where good .
Rating: 4 stars [4 of 5 Stars!]
By Kirk K.
Date: July 24, 2025
Thank God for electric fuel pump, bleeds back be there a month of Sundays with a mechanical pump
Rating: 5 stars [5 of 5 Stars!]
By Kirk K.
Date: July 24, 2025
Thank God for electric fuel pump, bleeds back be there a month of Sundays with a mechanical pump
Rating: 3 stars [3 of 5 Stars!]
By Sheephead Slayer
Date: November 05, 2024
I am doing a repower on my old 1993 Sea Nymph 190 Stinger deck boat, and I decided brand new fuel lines were in order. I had a impossible time reaching into a small space to get a proper 3/8 USCG rated fuel line to slide onto my old fitting, but I was able to remove it, cleaned it, and found it was sized for more like a 7'16 hose. Searching for a replacement bought me to choosing this item, it is more expensive than others here, but, looked to be of good quality. The pictures show it is well made, sized more for a 3/8 hose, and has well machined 1/4 NPT threads that match the old fitting exactly. Blowing air into it definitely tested its ability to check flow in one direction. I will be installing this very soon to get the boat back in service.
Rating: 5 stars [5 of 5 Stars!]
Items 1 - 6 of 19 reviews
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