Conbraco 10-408-05 3/4" Female x 3/4" Female 30 PSI Pressure Relief Valve
The Conbraco 10-408-05 is a capacity-certified pressure relief valve designed to protect hot water boilers and heating systems from excessive water pressure and thermal expansion. Built from durable brass with a plain finish, this valve ensures reliable, long-lasting operation in residential and commercial hydronic systems.
✅ 3/4" female inlet & outlet
✅ 30 PSI blow-off rating
✅ Max 535,000 BTU capacity
✅ Water-only applications – not for steam
✅ Complies with ASME Section IV requirements
Key Features ✅
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✅ 3/4" female NPT inlet and outlet
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✅ 30 PSI pressure relief – protects against overpressure
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✅ Max capacity 535,000 BTU – ideal for residential and commercial boilers
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✅ Plain brass finish – durable, corrosion-resistant
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✅ Water-only applications – ensures safe operation
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✅ Capacity-certified – meets ASME Section IV standards
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✅ Direct replacement for multiple OEM models
Technical Specifications 📝
| Specification | Details |
|---|
| Part Number |
10-408-05 |
| Type |
Pressure Relief Valve |
| Inlet Size |
3/4" Female NPT |
| Outlet Size |
3/4" Female NPT |
| Blow-Off Pressure |
30 PSI |
| Max Capacity |
535,000 BTU |
| Material |
Brass |
| Finish |
Plain |
| Application |
Hot water boilers and heating systems |
| Steam Use |
Not suitable |
Cross-Reference / Replacement Chart 🛠️
| Brand / Manufacturer | Model / Part Number |
|---|
| Peerless |
50501 |
| Crown Boiler |
95-040 |
| Velocity Boiler Works |
95-040 |
| Slant Fin |
400103, 400-103-000 |
Common Symptoms Solved ⚡
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❌ Overpressure in hot water heating systems
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❌ Water hammer or pipe damage due to thermal expansion
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❌ Boiler pressure exceeding safe limits
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❌ Frequent tripping of system pressure controls
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❌ Inoperative or leaking OEM relief valves
Shopping Tips 🛒
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✅ Ensure valve is for water only – do not use on steam systems
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✅ Confirm pipe thread size – 3/4" female NPT inlet & outlet
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✅ Check BTU rating – max 535,000 BTU
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✅ Use OEM or cross-reference replacement numbers for compatibility
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✅ Inspect and replace valves periodically to maintain safe system operation
Frequently Asked Questions (FAQ) ❓
Q: Can this valve be used on steam boilers?
✅ No, this valve is designed for water-only applications.
Q: What size connections does it have?
✅ 3/4" female NPT inlet and outlet.
Q: What is the blow-off pressure?
✅ 30 PSI.
Q: Which OEM parts does this replace?
✅ Peerless 50501, Crown Boiler 95-040, Velocity Boiler Works 95-040, Slant Fin 400103 / 400-103-000.
Q: What is the maximum capacity?
✅ 535,000 BTU.
