---
product_id: 7916056
title: "684-4 1/4\" MNPT Male Tank Valve, includes Protective Caps (Pack of 2)"
brand: "milton"
price: "$23.92"
currency: USD
in_stock: true
reviews_count: 13
category: "Milton"
url: https://www.desertcart.us/products/7916056-684-4-1-4-mnpt-male-tank-valve-includes-protective
store_origin: US
region: United States of America
---

# Prevents air leaks up to 200 PSI 1/4" MNPT male thread for universal fit Durable brass construction with protective caps 684-4 1/4" MNPT Male Tank Valve, includes Protective Caps (Pack of 2)

**Brand:** milton
**Price:** $23.92
**Availability:** ✅ In Stock

## Summary

> 💨 Lock in your air, lock out the leaks — the pro’s choice for airtight performance!

## Quick Answers

- **What is this?** 684-4 1/4" MNPT Male Tank Valve, includes Protective Caps (Pack of 2) by milton
- **How much does it cost?** $23.92 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.us](https://www.desertcart.us/products/7916056-684-4-1-4-mnpt-male-tank-valve-includes-protective)

## Best For

- milton enthusiasts

## Why This Product

- Trusted milton brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Built to Last:** Robust brass body paired with protective plastic caps for long-term durability and corrosion resistance.
- • **Trusted Legacy:** Milton quality since 1943—industry-leading air accessories trusted by pros across automotive, industrial, and heavy-duty markets.
- • **Leak-Proof Precision:** Engineered to lock in air pressure and eliminate costly leaks during vessel filling.
- • **Universal Compatibility:** Standard 1/4" MNPT threading ensures seamless integration with most air compressors and accessories.
- • **Pressure-Ready Performance:** Rated for safe operation up to 200 PSI, perfect for professional and DIY air systems.

## Overview

The Milton S-684-4 1/4" MNPT Male Tank Valve is a precision-engineered brass valve designed to prevent air leakage during vessel filling. Featuring a universal 1/4" male national pipe thread and protective plastic caps, it supports safe operation up to 200 PSI. Trusted since 1943, Milton delivers durable, leak-proof air accessories favored by professionals across automotive, industrial, and heavy-duty sectors.

## Description

Our Milton 1/4" MNPT tank valves are made to be used with an air compressor to prevent air from leaking out when filling vessels. A standard core valve and plastic cap are included giving the product an overall length of 1.5”. Do not exceed 200 PSI when using this tank valve.

Review: Airtight and great build quality - Great item, I used it to make a DIY pressure tester, works great, airtight, and the construction is good as well. I've had different types of Schrader valves and ball valves, and I've had some where there were some cracks in the brass when they were casting it, and over time, it leaked. This one doesn't seem like it would suffer from the same fate!
Review: Used as adapter for Dewalt and AstroAl chuck- perfect - Used this Milton 1/4” NPT tank valve and an Astro Al closed air chuck on a Dewalt DCC020I 20v air compressor (with LA-CO yellow has lime tape) and love it. The screw on/off connector of the Dewalt is awesome and will last longer. But for the airbags on the back of my truck screwing it off would drop the PSI a few and I was getting tired of that. I used this adapter to fit the AstroAl chuck to those Dewalt threads I’m happy with that. With the chuck not on a valve stem, if I turn the compressor on it’ll build to the set PSI fast and stop. Holds are tight, no leaks with the gas line tape used and this adapter. So after filling my tires and airbags I clip it right off. Perfect. Only down side is I then press the chuck stem against the screw of my rock tamer mud flaps to release the air from the Dewalt air compressor Line (otherwise the line still has pressure and is stiff), and this adapter has such good tolerances no air leaks). But it keeps everything right at the level I set it to be. All parts are perfect fits and hold great. A buddy and I put Firestone ride right airbags on his truck a few days ago, and he loved my Dewalt air compressor (he has tons of dewalt 20v stuff already and got me turned to Dewalt). So when he gets his I’ll be giving him the second air chuck and the second Milton 1/4” NPT tank valve.

## Features

- Prevents Air from Leaking: This handy tank valve helps prevent the loss of air when filling vessels with an air compressor
- Dimensions: Overall length including the plastic cap is 1.5”. The cap thread size is .305-32
- Maximum Air Pressure of 200 PSI: To ensure safe use of this tank valve, it is recommended that the air pressure be kept at a maximum of 200 PSI
- NPT: This tank valve has a 1/4" male national pipe thread
- #1 Source for Quality Air Accessories: Since 1943, Milton has been providing quality accessories to the Automotive, Industrial, Hardware, Agriculture, Heavy-Duty Fleet and MRO markets
- Milton is your number 1 source for Quality Air Accessories
- Since 1943 Milton has been producing Quality Air Accessories
- Milton covers automotive, industrial, hardware, agriculture, heavy-duty fleet and MRO markets

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B001PLI4BA |
| Best Sellers Rank | #76,844 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #215 in Air-Compressor Accessories |
| Brand Name | Milton |
| Connector Type | Cap |
| Customer Reviews | 4.7 4.7 out of 5 stars (2,085) |
| Exterior Finish | Plastic |
| Global Trade Identification Number | 00030937400383 |
| Included Components | 1/4" MNPT Male Tank Valve |
| Inlet Connection Size | 0.25 Inches |
| Inlet Connection Type | National Pipe Tapered |
| Item Dimensions | 2 x 1 x 1 inches |
| Item Type Name | 1/4" MNPT Male Tank Valve |
| Item Weight | 0.05 Pounds |
| Manufacturer | Milton |
| Material Type | Brass |
| Maximum Pressure | 200 Pound per Square Inch |
| Model Number | S-684-4 |
| Number of Pieces | 1 |
| Number of Ports | 2 |
| Outlet Connection Size | 0.25 Inches |
| Outlet Connection Type | MNPT |
| Size | Pack of 2 |
| Specification Met | Meets general industry standards for air compressor tank valves |
| Thread Size | 1/4" |
| Thread Type | NPT |
| UPC | 031113196373 735090074302 069060287356 030937400383 |
| Unit Count | 2.0 Count |
| Valve Type | Male Tank Valve |

## Product Details

- **Brand:** Milton
- **Exterior Finish:** Plastic
- **Inlet Connection Size:** 0.25 Inches
- **Inlet Connection Type:** National Pipe Tapered
- **Item dimensions L x W x H:** 2 x 1 x 1 inches
- **Material:** Brass
- **Maximum Operating Pressure:** 200 Pound per Square Inch
- **Number of Ports:** 2
- **Outlet Connection Size:** 0.25 Inches
- **Outlet Connection Type:** MNPT

## Images

![684-4 1/4" MNPT Male Tank Valve, includes Protective Caps (Pack of 2) - Image 1](https://m.media-amazon.com/images/I/6136lcD4a-L.jpg)

## Available Options

This product comes in different **Size** options.

## Questions & Answers

**Q: How big is the other side diameter?**
A: Shrader valve (same as bicycle and automotive tires)

**Q: 1/4" male on one end and shrader male on the the other end? Remove the core to make it a stright pass though for another 1/4 fitting? Works?**
A: If you mean to use it as a ¼" nipple, why would you?  Besides, the schrader end isn't ¼" NPT.

**Q: Why are these fittings made out of brass? Is pipe dope or teflon tape necessary on the threads?**
A: The rigidity of steel might allow it leak - brass is good - Teflon tape is small insurance- do it and move on !

**Q: Can i mount this on both ends of a venturi tube in my home irrigation system (sch40 pvc) to measure the water pressure drop?**
A: I suppose it would work. I guess u will tap the tube so u will get a tight connection.

## Customer Reviews

### ⭐⭐⭐⭐⭐ Airtight and great build quality
*by T***M on December 3, 2025*

Great item, I used it to make a DIY pressure tester, works great, airtight, and the construction is good as well. I've had different types of Schrader valves and ball valves, and I've had some where there were some cracks in the brass when they were casting it, and over time, it leaked. This one doesn't seem like it would suffer from the same fate!

### ⭐⭐⭐⭐⭐ Used as adapter for Dewalt and AstroAl chuck- perfect
*by C***. on March 7, 2020*

Used this Milton 1/4” NPT tank valve and an Astro Al closed air chuck on a Dewalt DCC020I 20v air compressor (with LA-CO yellow has lime tape) and love it. The screw on/off connector of the Dewalt is awesome and will last longer. But for the airbags on the back of my truck screwing it off would drop the PSI a few and I was getting tired of that. I used this adapter to fit the AstroAl chuck to those Dewalt threads I’m happy with that. With the chuck not on a valve stem, if I turn the compressor on it’ll build to the set PSI fast and stop. Holds are tight, no leaks with the gas line tape used and this adapter. So after filling my tires and airbags I clip it right off. Perfect. Only down side is I then press the chuck stem against the screw of my rock tamer mud flaps to release the air from the Dewalt air compressor Line (otherwise the line still has pressure and is stiff), and this adapter has such good tolerances no air leaks). But it keeps everything right at the level I set it to be. All parts are perfect fits and hold great. A buddy and I put Firestone ride right airbags on his truck a few days ago, and he loved my Dewalt air compressor (he has tons of dewalt 20v stuff already and got me turned to Dewalt). So when he gets his I’ll be giving him the second air chuck and the second Milton 1/4” NPT tank valve.

### ⭐⭐⭐⭐⭐ No leaks, works great!
*by J***T on December 15, 2025*

No leaks, works great!

## Frequently Bought Together

- Milton S-684-4 1/4" MNPT Male Tank Valve, includes Protective Caps (Pack of 2)
- Tire Deflator Kit Universal Adjustable Pack of 4 Automatic for Cars, Trucks

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*Product available on Desertcart United States of America*
*Store origin: US*
*Last updated: 2026-04-23*