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Replacing Kraissl Transfer Valves
There are meaningful differences between a Kraissl transfer valve and a HYCOA transfer valve in how they're designed and how they operate — even though both serve the general function of diverting or switching flow paths in a system.
Download Comparison PDFTwo Valves, Two Different Approaches
Both Kraissl and HYCOA transfer valves do similar jobs — diverting or switching flow — but the internal mechanisms and performance expectations differ significantly. Understanding those differences helps you make the right choice for your application.
Kraissl valves are robust, traditional plug-type diverters with metal plugs and dependable sealing mechanisms. HYCOA's JR-33 valves use a patented shoe seal and lockdown design that provides smoother switching, virtually zero leakage, and lower maintenance.
If your priority is highest reliability and minimal leakage in critical systems, HYCOA generally offers an advanced design. If your focus is simple, heavy-duty divergence of flow paths, Kraissl plug-type valves are a proven choice.
Bottom Line
For critical fluid systems — turbine lube oil, API 614 skids, power generation — HYCOA's patented Shoe Seal design delivers performance that traditional plug-type valves simply cannot match.
HYCOA Advantages
Kraissl Limitations
Comparison Guide — PDF
Download the full HYCOA vs. Kraissl comparison document for your engineering files or to share with your team.
Download PDFWhy HYCOA Outperforms Kraissl
Six engineering advantages that make the HYCOA JR-33 the preferred choice for critical fluid systems.
Zero Internal Leakage
Patented Shoe Seal mechanically locks into position — engineered to eliminate internal bypass regardless of cycles or wear.
Zero Frictional Drag
The shoe seal lifts completely during transfer — no drag, no pressure spike, no flow interruption.
No Lubrication Required
Eliminates grease fittings and packing adjustments — reduces maintenance cost and contamination risk.
Low Operating Torque
Smooth, consistent switching even in large sizes — no lifting jack or handle extensions needed.
Positive Mechanical Lockdown
No springs — mechanically locked in both active and standby positions for stable, reliable sealing.
API 598 & API 614 Rated
Designed and tested per API standards for special-purpose rotating equipment lubrication systems.
Core Operating Principles
Kraissl Transfer Valves
Tapered plug diverter — traditional all-metal design
Kraissl valves are mechanical diverter/plug valves used to divert flow between two paths — often to parallel equipment like filters or heat exchangers — while maintaining continuous flow. They use a tapered metal-to-metal valve plug that is rotated into position to open one flow path and close the other.
- Tapered metal-to-metal valve plug rotated into position
- Locking flange and external packing for service without full disassembly
- Rugged all-metal construction with simple mechanical sealing
- Proven design in many general industrial installations
- Good for duplexing filters, heat exchangers, and tanks
- Packing adjustments are external and field-serviceable
HYCOA Transfer Valves
Patented Shoe Seal Lockdown — precision engineered sealing
HYCOA (e.g., JR-33 series) uses a patented Shoe Seal Lockdown design that's very different from a simple tapered plug. Instead of relying on metal-to-metal contact alone, HYCOA's design uses resilient shoe seals that mechanically lock into place and provide zero internal leakage when switching paths.
- Zero Internal Leakage
- Zero Frictional Drag
- No Lubrication Required
- Low Operating Torque
- Positive Mechanical Lockdown
- API 598 & API 614 Rated
Key Design Differences
Sealing Mechanism
Kraissl
- Uses tapered plug and seat (metal-to-metal) sealing
- Seal performance depends on metal contact and valve machining
- External packing required — periodic adjustment needed
- Leakage increases as packing wears over time
HYCOA
- Uses patented Shoe Seal (resilient seals) for positive containment
- Designed to eliminate internal bypass leakage and resist wear
- Mechanically locked — not dependent on spring force — for stable sealing
- No packing — no adjustment, no degradation over time
Takeaway: HYCOA seals deliver true zero leakage and lower friction than traditional plug-style designs.
Ease of Operation
Kraissl
- Manual plug rotates under load — friction against seat
- May require optional lifting jack for larger sizes
- Packing adjustments are external but still require maintenance
- Lubrication required at grease fittings
HYCOA
- Shoe seal lifts completely during transfer — zero frictional drag
- Lower operating torque — no lifting jack needed
- Designed for smooth, consistent switching even after many cycles
- No lubrication required — maintenance-free sealing
Construction & Application Focus
Kraissl
- Cast bodies (iron, steel, stainless) with removable plug
- Good for general industrial use — duplexing filters, heat exchangers, tanks
- Traditional, proven design in many installations
HYCOA
- Heavy-duty fabricated construction with precision sealing
- Often chosen for critical fluid systems like turbine lube oil
- Lower pressure drop, longevity, and high reliability emphasized
When to Choose Each
Choose Kraissl when…
- Simple, heavy-duty divergence of flow paths is the priority
- General industrial duplexing applications
- Direct replacement of existing Kraissl installations
Choose HYCOA when…
- Highest reliability and minimal leakage in critical systems
- Turbine lube oil, API 614, or power generation applications
- Upgrading from Kraissl for improved sealing performance
- Zero-maintenance sealing is required
Full Comparison Table
12-point side-by-side comparison of HYCOA JR-33 vs. Kraissl transfer valves
| Feature | Kraissl | HYCOA JR-33 |
|---|---|---|
| Valve Type | Tapered plug diverter | Shoe Seal transfer valve |
| Sealing Method | Metal-to-metal plug + packing | Patented resilient Shoe Seal |
| Internal Leakage | Depends on fit & packing condition | Engineered zero leakage |
| Frictional Drag During Transfer | Plug rotates under load — friction & wear | Shoe lifts completely — zero drag |
| Lubrication Required | Yes — grease fittings required | No — maintenance-free sealing |
| Operating Torque | Moderate to high (may need lifting jack) | Low — smooth consistent switching |
| Packing Adjustments | External packing, periodic adjustment | None required |
| Mechanical Lockdown | Locking flange on plug | Positive mechanical lockdown — no springs |
| API Standards | General industrial | API 598 & API 614 rated |
| Drop-In Replacement | — | Yes — matches Kraissl bolt patterns & face-to-face |
| Body Construction | Cast iron, steel, or stainless | Heavy-duty fabricated construction |
| Best Application | General industrial duplexing | Critical fluid systems — turbine lube oil, API 614 |
Find Your HYCOA Replacement Model
Use our searchable cross-reference table to find the exact HYCOA JR-33 model that replaces your Kraissl valve.
HYCOA Transfer Valve Products
Frequently Asked Questions
Ready to Upgrade from Kraissl?
Our team can help you identify the right HYCOA replacement for your existing Kraissl installation — including dimensional cross-references and retrofit guidance.
HYCOA® JR-33
Select a Valve
- JR3
3-Way Transfer Valve
Single flow path switching
- TP
3-Way Twin-Pak
Inlet + outlet in one body
- 6SS
6-Way Same-Side
Most popular duplex config
- 6IL
6-Way Inline
Straight-through piping
- 6OS
6-Way Opposite Side
Opposing supply & return lines
- HIC
HICORP Transfer Valves
2″ – 12″ large-bore service
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